Merge branch 'master' into truncate-internal-eval

# Conflicts:
#	bot/utils/__init__.py

51 files changed, 1374 insertions, 492 deletions

diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 000000000..8760b35ec
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,32 @@
+name: "Code scanning - action"
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 12 * * *'
+
+jobs:
+  CodeQL-Build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        languages: python
+
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1
diff --git a/Pipfile b/Pipfile
index b42ca6d58..33be99587 100644
--- a/Pipfile
+++ b/Pipfile
@@ -50,4 +50,5 @@ precommit = "pre-commit install"
 build = "docker build -t pythondiscord/bot:latest -f Dockerfile ."
 push = "docker push pythondiscord/bot:latest"
 test = "coverage run -m unittest"
+html = "coverage html"
 report = "coverage report"
diff --git a/bot/__main__.py b/bot/__main__.py
index aa1d1aee8..4e0d4a111 100644
--- a/bot/__main__.py
+++ b/bot/__main__.py
@@ -3,7 +3,9 @@ import logging
 import discord
 import sentry_sdk
 from discord.ext.commands import when_mentioned_or
+from sentry_sdk.integrations.aiohttp import AioHttpIntegration
 from sentry_sdk.integrations.logging import LoggingIntegration
+from sentry_sdk.integrations.redis import RedisIntegration
 
 from bot import constants, patches
 from bot.bot import Bot
@@ -15,7 +17,11 @@ sentry_logging = LoggingIntegration(
 
 sentry_sdk.init(
     dsn=constants.Bot.sentry_dsn,
-    integrations=[sentry_logging]
+    integrations=[
+        sentry_logging,
+        AioHttpIntegration(),
+        RedisIntegration(),
+    ]
 )
 
 bot = Bot(
diff --git a/bot/cogs/antimalware.py b/bot/cogs/antimalware.py
index 66b5073e8..ea257442e 100644
--- a/bot/cogs/antimalware.py
+++ b/bot/cogs/antimalware.py
@@ -1,4 +1,5 @@
 import logging
+import typing as t
 from os.path import splitext
 
 from discord import Embed, Message, NotFound
@@ -9,6 +10,27 @@ from bot.constants import AntiMalware as AntiMalwareConfig, Channels, STAFF_ROLE
 
 log = logging.getLogger(__name__)
 
+PY_EMBED_DESCRIPTION = (
+    "It looks like you tried to attach a Python file - "
+    f"please use a code-pasting service such as {URLs.site_schema}{URLs.site_paste}"
+)
+
+TXT_EMBED_DESCRIPTION = (
+    "**Uh-oh!** It looks like your message got zapped by our spam filter. "
+    "We currently don't allow `.txt` attachments, so here are some tips to help you travel safely: \n\n"
+    "• If you attempted to send a message longer than 2000 characters, try shortening your message "
+    "to fit within the character limit or use a pasting service (see below) \n\n"
+    "• If you tried to show someone your code, you can use codeblocks \n(run `!code-blocks` in "
+    "{cmd_channel_mention} for more information) or use a pasting service like: "
+    f"\n\n{URLs.site_schema}{URLs.site_paste}"
+)
+
+DISALLOWED_EMBED_DESCRIPTION = (
+    "It looks like you tried to attach file type(s) that we do not allow ({blocked_extensions_str}). "
+    f"We currently allow the following file types: **{', '.join(AntiMalwareConfig.whitelist)}**.\n\n"
+    "Feel free to ask in {meta_channel_mention} if you think this is a mistake."
+)
+
 
 class AntiMalware(Cog):
     """Delete messages which contain attachments with non-whitelisted file extensions."""
@@ -29,34 +51,20 @@ class AntiMalware(Cog):
             return
 
         embed = Embed()
-        file_extensions = {splitext(attachment.filename.lower())[1] for attachment in message.attachments}
-        extensions_blocked = file_extensions - set(AntiMalwareConfig.whitelist)
+        extensions_blocked = self.get_disallowed_extensions(message)
         blocked_extensions_str = ', '.join(extensions_blocked)
         if ".py" in extensions_blocked:
             # Short-circuit on *.py files to provide a pastebin link
-            embed.description = (
-                "It looks like you tried to attach a Python file - "
-                f"please use a code-pasting service such as {URLs.site_schema}{URLs.site_paste}"
-            )
+            embed.description = PY_EMBED_DESCRIPTION
         elif ".txt" in extensions_blocked:
             # Work around Discord AutoConversion of messages longer than 2000 chars to .txt
             cmd_channel = self.bot.get_channel(Channels.bot_commands)
-            embed.description = (
-                "**Uh-oh!** It looks like your message got zapped by our spam filter. "
-                "We currently don't allow `.txt` attachments, so here are some tips to help you travel safely: \n\n"
-                "• If you attempted to send a message longer than 2000 characters, try shortening your message "
-                "to fit within the character limit or use a pasting service (see below) \n\n"
-                "• If you tried to show someone your code, you can use codeblocks \n(run `!code-blocks` in "
-                f"{cmd_channel.mention} for more information) or use a pasting service like: "
-                f"\n\n{URLs.site_schema}{URLs.site_paste}"
-            )
+            embed.description = TXT_EMBED_DESCRIPTION.format(cmd_channel_mention=cmd_channel.mention)
         elif extensions_blocked:
-            whitelisted_types = ', '.join(AntiMalwareConfig.whitelist)
             meta_channel = self.bot.get_channel(Channels.meta)
-            embed.description = (
-                f"It looks like you tried to attach file type(s) that we do not allow ({blocked_extensions_str}). "
-                f"We currently allow the following file types: **{whitelisted_types}**.\n\n"
-                f"Feel free to ask in {meta_channel.mention} if you think this is a mistake."
+            embed.description = DISALLOWED_EMBED_DESCRIPTION.format(
+                blocked_extensions_str=blocked_extensions_str,
+                meta_channel_mention=meta_channel.mention,
             )
 
         if embed.description:
@@ -73,6 +81,13 @@ class AntiMalware(Cog):
             except NotFound:
                 log.info(f"Tried to delete message `{message.id}`, but message could not be found.")
 
+    @classmethod
+    def get_disallowed_extensions(cls, message: Message) -> t.Iterable[str]:
+        """Get an iterable containing all the disallowed extensions of attachments."""
+        file_extensions = {splitext(attachment.filename.lower())[1] for attachment in message.attachments}
+        extensions_blocked = file_extensions - set(AntiMalwareConfig.whitelist)
+        return extensions_blocked
+
 
 def setup(bot: Bot) -> None:
     """Load the AntiMalware cog."""
diff --git a/bot/cogs/clean.py b/bot/cogs/clean.py
index b5d9132cb..368d91c85 100644
--- a/bot/cogs/clean.py
+++ b/bot/cogs/clean.py
@@ -1,16 +1,16 @@
 import logging
 import random
 import re
-from typing import Optional
+from typing import Iterable, Optional
 
 from discord import Colour, Embed, Message, TextChannel, User
+from discord.ext import commands
 from discord.ext.commands import Cog, Context, group
 
 from bot.bot import Bot
 from bot.cogs.moderation import ModLog
 from bot.constants import (
-    Channels, CleanMessages, Colours, Event,
-    Icons, MODERATION_ROLES, NEGATIVE_REPLIES
+    Channels, CleanMessages, Colours, Event, Icons, MODERATION_ROLES, NEGATIVE_REPLIES
 )
 from bot.decorators import with_role
 
@@ -41,10 +41,10 @@ class Clean(Cog):
         self,
         amount: int,
         ctx: Context,
+        channels: Iterable[TextChannel],
         bots_only: bool = False,
         user: User = None,
         regex: Optional[str] = None,
-        channel: Optional[TextChannel] = None
     ) -> None:
         """A helper function that does the actual message cleaning."""
         def predicate_bots_only(message: Message) -> bool:
@@ -110,48 +110,39 @@ class Clean(Cog):
             predicate = None                     # Delete all messages
 
         # Default to using the invoking context's channel
-        if not channel:
-            channel = ctx.channel
+        if not channels:
+            channels = [ctx.channel]
+
+        # Delete the invocation first
+        self.mod_log.ignore(Event.message_delete, ctx.message.id)
+        await ctx.message.delete()
 
-        # Look through the history and retrieve message data
         messages = []
         message_ids = []
         self.cleaning = True
-        invocation_deleted = False
-
-        # To account for the invocation message, we index `amount + 1` messages.
-        async for message in channel.history(limit=amount + 1):
 
-            # If at any point the cancel command is invoked, we should stop.
-            if not self.cleaning:
-                return
+        # Find the IDs of the messages to delete. IDs are needed in order to ignore mod log events.
+        for channel in channels:
+            async for message in channel.history(limit=amount):
 
-            # Always start by deleting the invocation
-            if not invocation_deleted:
-                self.mod_log.ignore(Event.message_delete, message.id)
-                await message.delete()
-                invocation_deleted = True
-                continue
+                # If at any point the cancel command is invoked, we should stop.
+                if not self.cleaning:
+                    return
 
-            # If the message passes predicate, let's save it.
-            if predicate is None or predicate(message):
-                message_ids.append(message.id)
-                messages.append(message)
+                # If the message passes predicate, let's save it.
+                if predicate is None or predicate(message):
+                    message_ids.append(message.id)
 
         self.cleaning = False
 
-        # We should ignore the ID's we stored, so we don't get mod-log spam.
+        # Now let's delete the actual messages with purge.
         self.mod_log.ignore(Event.message_delete, *message_ids)
-
-        # Use bulk delete to actually do the cleaning. It's far faster.
-        await channel.purge(
-            limit=amount,
-            check=predicate
-        )
+        for channel in channels:
+            messages += await channel.purge(limit=amount, check=predicate)
 
         # Reverse the list to restore chronological order
         if messages:
-            messages = list(reversed(messages))
+            messages = reversed(messages)
             log_url = await self.mod_log.upload_log(messages, ctx.author.id)
         else:
             # Can't build an embed, nothing to clean!
@@ -163,8 +154,10 @@ class Clean(Cog):
             return
 
         # Build the embed and send it
+        target_channels = ", ".join(channel.mention for channel in channels)
+
         message = (
-            f"**{len(message_ids)}** messages deleted in <#{channel.id}> by **{ctx.author.name}**\n\n"
+            f"**{len(message_ids)}** messages deleted in {target_channels} by **{ctx.author.name}**\n\n"
             f"A log of the deleted messages can be found [here]({log_url})."
         )
 
@@ -189,10 +182,10 @@ class Clean(Cog):
         ctx: Context,
         user: User,
         amount: Optional[int] = 10,
-        channel: TextChannel = None
+        channels: commands.Greedy[TextChannel] = None
     ) -> None:
         """Delete messages posted by the provided user, stop cleaning after traversing `amount` messages."""
-        await self._clean_messages(amount, ctx, user=user, channel=channel)
+        await self._clean_messages(amount, ctx, user=user, channels=channels)
 
     @clean_group.command(name="all", aliases=["everything"])
     @with_role(*MODERATION_ROLES)
@@ -200,10 +193,10 @@ class Clean(Cog):
         self,
         ctx: Context,
         amount: Optional[int] = 10,
-        channel: TextChannel = None
+        channels: commands.Greedy[TextChannel] = None
     ) -> None:
         """Delete all messages, regardless of poster, stop cleaning after traversing `amount` messages."""
-        await self._clean_messages(amount, ctx, channel=channel)
+        await self._clean_messages(amount, ctx, channels=channels)
 
     @clean_group.command(name="bots", aliases=["bot"])
     @with_role(*MODERATION_ROLES)
@@ -211,10 +204,10 @@ class Clean(Cog):
         self,
         ctx: Context,
         amount: Optional[int] = 10,
-        channel: TextChannel = None
+        channels: commands.Greedy[TextChannel] = None
     ) -> None:
         """Delete all messages posted by a bot, stop cleaning after traversing `amount` messages."""
-        await self._clean_messages(amount, ctx, bots_only=True, channel=channel)
+        await self._clean_messages(amount, ctx, bots_only=True, channels=channels)
 
     @clean_group.command(name="regex", aliases=["word", "expression"])
     @with_role(*MODERATION_ROLES)
@@ -223,10 +216,10 @@ class Clean(Cog):
         ctx: Context,
         regex: str,
         amount: Optional[int] = 10,
-        channel: TextChannel = None
+        channels: commands.Greedy[TextChannel] = None
     ) -> None:
         """Delete all messages that match a certain regex, stop cleaning after traversing `amount` messages."""
-        await self._clean_messages(amount, ctx, regex=regex, channel=channel)
+        await self._clean_messages(amount, ctx, regex=regex, channels=channels)
 
     @clean_group.command(name="stop", aliases=["cancel", "abort"])
     @with_role(*MODERATION_ROLES)
diff --git a/bot/cogs/duck_pond.py b/bot/cogs/duck_pond.py
index 37d1786a2..5b6a7fd62 100644
--- a/bot/cogs/duck_pond.py
+++ b/bot/cogs/duck_pond.py
@@ -7,7 +7,7 @@ from discord.ext.commands import Cog
 
 from bot import constants
 from bot.bot import Bot
-from bot.utils.messages import send_attachments
+from bot.utils.messages import send_attachments, sub_clyde
 
 log = logging.getLogger(__name__)
 
@@ -58,7 +58,7 @@ class DuckPond(Cog):
         try:
             await self.webhook.send(
                 content=content,
-                username=username,
+                username=sub_clyde(username),
                 avatar_url=avatar_url,
                 embed=embed
             )
diff --git a/bot/cogs/filtering.py b/bot/cogs/filtering.py
index 1d9fddb12..76ea68660 100644
--- a/bot/cogs/filtering.py
+++ b/bot/cogs/filtering.py
@@ -1,10 +1,13 @@
+import asyncio
 import logging
 import re
-from typing import Optional, Union
+from datetime import datetime, timedelta
+from typing import List, Mapping, Optional, Union
 
+import dateutil
 import discord.errors
 from dateutil.relativedelta import relativedelta
-from discord import Colour, Member, Message, TextChannel
+from discord import Colour, HTTPException, Member, Message, NotFound, TextChannel
 from discord.ext.commands import Cog
 from discord.utils import escape_markdown
 
@@ -14,6 +17,9 @@ from bot.constants import (
     Channels, Colours,
     Filter, Icons, URLs
 )
+from bot.utils.redis_cache import RedisCache
+from bot.utils.scheduling import Scheduler
+from bot.utils.time import wait_until
 
 log = logging.getLogger(__name__)
 
@@ -40,6 +46,8 @@ TOKEN_WATCHLIST_PATTERNS = [
 ]
 WATCHLIST_PATTERNS = WORD_WATCHLIST_PATTERNS + TOKEN_WATCHLIST_PATTERNS
 
+DAYS_BETWEEN_ALERTS = 3
+
 
 def expand_spoilers(text: str) -> str:
     """Return a string containing all interpretations of a spoilered message."""
@@ -49,11 +57,20 @@ def expand_spoilers(text: str) -> str:
     )
 
 
-class Filtering(Cog):
+OFFENSIVE_MSG_DELETE_TIME = timedelta(days=Filter.offensive_msg_delete_days)
+
+
+class Filtering(Cog, Scheduler):
     """Filtering out invites, blacklisting domains, and warning us of certain regular expressions."""
 
+    # Redis cache mapping a user ID to the last timestamp a bad nickname alert was sent
+    name_alerts = RedisCache()
+
     def __init__(self, bot: Bot):
         self.bot = bot
+        super().__init__()
+
+        self.name_lock = asyncio.Lock()
 
         staff_mistake_str = "If you believe this was a mistake, please let staff know!"
         self.filters = {
@@ -66,7 +83,8 @@ class Filtering(Cog):
                 "notification_msg": (
                     "Your post has been removed for abusing Unicode character rendering (aka Zalgo text). "
                     f"{staff_mistake_str}"
-                )
+                ),
+                "schedule_deletion": False
             },
             "filter_invites": {
                 "enabled": Filter.filter_invites,
@@ -77,7 +95,8 @@ class Filtering(Cog):
                 "notification_msg": (
                     f"Per Rule 6, your invite link has been removed. {staff_mistake_str}\n\n"
                     r"Our server rules can be found here: <https://pythondiscord.com/pages/rules>"
-                )
+                ),
+                "schedule_deletion": False
             },
             "filter_domains": {
                 "enabled": Filter.filter_domains,
@@ -87,22 +106,27 @@ class Filtering(Cog):
                 "user_notification": Filter.notify_user_domains,
                 "notification_msg": (
                     f"Your URL has been removed because it matched a blacklisted domain. {staff_mistake_str}"
-                )
+                ),
+                "schedule_deletion": False
             },
             "watch_regex": {
                 "enabled": Filter.watch_regex,
                 "function": self._has_watch_regex_match,
                 "type": "watchlist",
                 "content_only": True,
+                "schedule_deletion": True
             },
             "watch_rich_embeds": {
                 "enabled": Filter.watch_rich_embeds,
                 "function": self._has_rich_embed,
                 "type": "watchlist",
                 "content_only": False,
-            },
+                "schedule_deletion": False
+            }
         }
 
+        self.bot.loop.create_task(self.reschedule_offensive_msg_deletion())
+
     @property
     def mod_log(self) -> ModLog:
         """Get currently loaded ModLog cog instance."""
@@ -112,6 +136,7 @@ class Filtering(Cog):
     async def on_message(self, msg: Message) -> None:
         """Invoke message filter for new messages."""
         await self._filter_message(msg)
+        await self.check_bad_words_in_name(msg.author)
 
     @Cog.listener()
     async def on_message_edit(self, before: Message, after: Message) -> None:
@@ -126,6 +151,55 @@ class Filtering(Cog):
             delta = relativedelta(after.edited_at, before.edited_at).microseconds
         await self._filter_message(after, delta)
 
+    @staticmethod
+    def get_name_matches(name: str) -> List[re.Match]:
+        """Check bad words from passed string (name). Return list of matches."""
+        matches = []
+        for pattern in WATCHLIST_PATTERNS:
+            if match := pattern.search(name):
+                matches.append(match)
+        return matches
+
+    async def check_send_alert(self, member: Member) -> bool:
+        """When there is less than 3 days after last alert, return `False`, otherwise `True`."""
+        if last_alert := await self.name_alerts.get(member.id):
+            last_alert = datetime.utcfromtimestamp(last_alert)
+            if datetime.utcnow() - timedelta(days=DAYS_BETWEEN_ALERTS) < last_alert:
+                log.trace(f"Last alert was too recent for {member}'s nickname.")
+                return False
+
+        return True
+
+    async def check_bad_words_in_name(self, member: Member) -> None:
+        """Send a mod alert every 3 days if a username still matches a watchlist pattern."""
+        # Use lock to avoid race conditions
+        async with self.name_lock:
+            # Check whether the users display name contains any words in our blacklist
+            matches = self.get_name_matches(member.display_name)
+
+            if not matches or not await self.check_send_alert(member):
+                return
+
+            log.info(f"Sending bad nickname alert for '{member.display_name}' ({member.id}).")
+
+            log_string = (
+                f"**User:** {member.mention} (`{member.id}`)\n"
+                f"**Display Name:** {member.display_name}\n"
+                f"**Bad Matches:** {', '.join(match.group() for match in matches)}"
+            )
+
+            await self.mod_log.send_log_message(
+                icon_url=Icons.token_removed,
+                colour=Colours.soft_red,
+                title="Username filtering alert",
+                text=log_string,
+                channel_id=Channels.mod_alerts,
+                thumbnail=member.avatar_url
+            )
+
+            # Update time when alert sent
+            await self.name_alerts.set(member.id, datetime.utcnow().timestamp())
+
     async def _filter_message(self, msg: Message, delta: Optional[int] = None) -> None:
         """Filter the input message to see if it violates any of our rules, and then respond accordingly."""
         # Should we filter this message?
@@ -183,6 +257,20 @@ class Filtering(Cog):
                             if _filter["user_notification"]:
                                 await self.notify_member(msg.author, _filter["notification_msg"], msg.channel)
 
+                        # If the message is classed as offensive, we store it in the site db and
+                        # it will be deleted it after one week.
+                        if _filter["schedule_deletion"] and not is_private:
+                            delete_date = (msg.created_at + OFFENSIVE_MSG_DELETE_TIME).isoformat()
+                            data = {
+                                'id': msg.id,
+                                'channel_id': msg.channel.id,
+                                'delete_date': delete_date
+                            }
+
+                            await self.bot.api_client.post('bot/offensive-messages', json=data)
+                            self.schedule_task(msg.id, data)
+                            log.trace(f"Offensive message {msg.id} will be deleted on {delete_date}")
+
                         if is_private:
                             channel_str = "via DM"
                         else:
@@ -300,7 +388,7 @@ class Filtering(Cog):
 
         Attempts to catch some of common ways to try to cheat the system.
         """
-        # Remove backslashes to prevent escape character aroundfuckery like
+        # Remove backslashes to prevent escape character around fuckery like
         # discord\.gg/gdudes-pony-farm
         text = text.replace("\\", "")
 
@@ -369,6 +457,46 @@ class Filtering(Cog):
         except discord.errors.Forbidden:
             await channel.send(f"{filtered_member.mention} {reason}")
 
+    async def _scheduled_task(self, msg: dict) -> None:
+        """Delete an offensive message once its deletion date is reached."""
+        delete_at = dateutil.parser.isoparse(msg['delete_date']).replace(tzinfo=None)
+
+        await wait_until(delete_at)
+        await self.delete_offensive_msg(msg)
+
+    async def reschedule_offensive_msg_deletion(self) -> None:
+        """Get all the pending message deletion from the API and reschedule them."""
+        await self.bot.wait_until_ready()
+        response = await self.bot.api_client.get('bot/offensive-messages',)
+
+        now = datetime.utcnow()
+
+        for msg in response:
+            delete_at = dateutil.parser.isoparse(msg['delete_date']).replace(tzinfo=None)
+
+            if delete_at < now:
+                await self.delete_offensive_msg(msg)
+            else:
+                self.schedule_task(msg['id'], msg)
+
+    async def delete_offensive_msg(self, msg: Mapping[str, str]) -> None:
+        """Delete an offensive message, and then delete it from the db."""
+        try:
+            channel = self.bot.get_channel(msg['channel_id'])
+            if channel:
+                msg_obj = await channel.fetch_message(msg['id'])
+                await msg_obj.delete()
+        except NotFound:
+            log.info(
+                f"Tried to delete message {msg['id']}, but the message can't be found "
+                f"(it has been probably already deleted)."
+            )
+        except HTTPException as e:
+            log.warning(f"Failed to delete message {msg['id']}: status {e.status}")
+
+        await self.bot.api_client.delete(f'bot/offensive-messages/{msg["id"]}')
+        log.info(f"Deleted the offensive message with id {msg['id']}.")
+
 
 def setup(bot: Bot) -> None:
     """Load the Filtering cog."""
diff --git a/bot/cogs/help_channels.py b/bot/cogs/help_channels.py
index 70cef339a..187adfe51 100644
--- a/bot/cogs/help_channels.py
+++ b/bot/cogs/help_channels.py
@@ -5,8 +5,7 @@ import logging
 import random
 import typing as t
 from collections import deque
-from contextlib import suppress
-from datetime import datetime
+from datetime import datetime, timedelta, timezone
 from pathlib import Path
 
 import discord
@@ -15,6 +14,7 @@ from discord.ext import commands
 
 from bot import constants
 from bot.bot import Bot
+from bot.utils import RedisCache
 from bot.utils.checks import with_role_check
 from bot.utils.scheduling import Scheduler
 
@@ -22,7 +22,7 @@ log = logging.getLogger(__name__)
 
 ASKING_GUIDE_URL = "https://pythondiscord.com/pages/asking-good-questions/"
 MAX_CHANNELS_PER_CATEGORY = 50
-EXCLUDED_CHANNELS = (constants.Channels.how_to_get_help,)
+EXCLUDED_CHANNELS = (constants.Channels.how_to_get_help, constants.Channels.cooldown)
 
 HELP_CHANNEL_TOPIC = """
 This is a Python help channel. You can claim your own help channel in the Python Help: Available category.
@@ -99,13 +99,24 @@ class HelpChannels(Scheduler, commands.Cog):
     Help channels are named after the chemical elements in `bot/resources/elements.json`.
     """
 
+    # This cache tracks which channels are claimed by which members.
+    # RedisCache[discord.TextChannel.id, t.Union[discord.User.id, discord.Member.id]]
+    help_channel_claimants = RedisCache()
+
+    # This cache maps a help channel to whether it has had any
+    # activity other than the original claimant. True being no other
+    # activity and False being other activity.
+    # RedisCache[discord.TextChannel.id, bool]
+    unanswered = RedisCache()
+
+    # This dictionary maps a help channel to the time it was claimed
+    # RedisCache[discord.TextChannel.id, UtcPosixTimestamp]
+    claim_times = RedisCache()
+
     def __init__(self, bot: Bot):
         super().__init__()
 
         self.bot = bot
-        self.help_channel_claimants: (
-            t.Dict[discord.TextChannel, t.Union[discord.Member, discord.User]]
-        ) = {}
 
         # Categories
         self.available_category: discord.CategoryChannel = None
@@ -125,16 +136,6 @@ class HelpChannels(Scheduler, commands.Cog):
         self.on_message_lock = asyncio.Lock()
         self.init_task = self.bot.loop.create_task(self.init_cog())
 
-        # Stats
-
-        # This dictionary maps a help channel to the time it was claimed
-        self.claim_times: t.Dict[int, datetime] = {}
-
-        # This dictionary maps a help channel to whether it has had any
-        # activity other than the original claimant. True being no other
-        # activity and False being other activity.
-        self.unanswered: t.Dict[int, bool] = {}
-
     def cog_unload(self) -> None:
         """Cancel the init task and scheduled tasks when the cog unloads."""
         log.trace("Cog unload: cancelling the init_cog task")
@@ -197,7 +198,7 @@ class HelpChannels(Scheduler, commands.Cog):
 
     async def dormant_check(self, ctx: commands.Context) -> bool:
         """Return True if the user is the help channel claimant or passes the role check."""
-        if self.help_channel_claimants.get(ctx.channel) == ctx.author:
+        if await self.help_channel_claimants.get(ctx.channel.id) == ctx.author.id:
             log.trace(f"{ctx.author} is the help channel claimant, passing the check for dormant.")
             self.bot.stats.incr("help.dormant_invoke.claimant")
             return True
@@ -222,10 +223,11 @@ class HelpChannels(Scheduler, commands.Cog):
         log.trace("close command invoked; checking if the channel is in-use.")
         if ctx.channel.category == self.in_use_category:
             if await self.dormant_check(ctx):
-                with suppress(KeyError):
-                    del self.help_channel_claimants[ctx.channel]
 
+                # Remove the claimant and the cooldown role
+                await self.help_channel_claimants.delete(ctx.channel.id)
                 await self.remove_cooldown_role(ctx.author)
+
                 # Ignore missing task when cooldown has passed but the channel still isn't dormant.
                 self.cancel_task(ctx.author.id, ignore_missing=True)
 
@@ -284,6 +286,15 @@ class HelpChannels(Scheduler, commands.Cog):
             if channel.category_id == category.id and not self.is_excluded_channel(channel):
                 yield channel
 
+    async def get_in_use_time(self, channel_id: int) -> t.Optional[timedelta]:
+        """Return the duration `channel_id` has been in use. Return None if it's not in use."""
+        log.trace(f"Calculating in use time for channel {channel_id}.")
+
+        claimed_timestamp = await self.claim_times.get(channel_id)
+        if claimed_timestamp:
+            claimed = datetime.utcfromtimestamp(claimed_timestamp)
+            return datetime.utcnow() - claimed
+
     @staticmethod
     def get_names() -> t.List[str]:
         """
@@ -386,7 +397,7 @@ class HelpChannels(Scheduler, commands.Cog):
 
         log.trace("Initialising the cog.")
         await self.init_categories()
-        await self.reset_send_permissions()
+        await self.check_cooldowns()
 
         self.channel_queue = self.create_channel_queue()
         self.name_queue = self.create_name_queue()
@@ -546,19 +557,17 @@ class HelpChannels(Scheduler, commands.Cog):
 
         self.bot.stats.incr(f"help.dormant_calls.{caller}")
 
-        if channel.id in self.claim_times:
-            claimed = self.claim_times[channel.id]
-            in_use_time = datetime.now() - claimed
+        in_use_time = await self.get_in_use_time(channel.id)
+        if in_use_time:
             self.bot.stats.timing("help.in_use_time", in_use_time)
 
-        if channel.id in self.unanswered:
-            if self.unanswered[channel.id]:
-                self.bot.stats.incr("help.sessions.unanswered")
-            else:
-                self.bot.stats.incr("help.sessions.answered")
+        unanswered = await self.unanswered.get(channel.id)
+        if unanswered:
+            self.bot.stats.incr("help.sessions.unanswered")
+        elif unanswered is not None:
+            self.bot.stats.incr("help.sessions.answered")
 
         log.trace(f"Position of #{channel} ({channel.id}) is actually {channel.position}.")
-
         log.trace(f"Sending dormant message for #{channel} ({channel.id}).")
         embed = discord.Embed(description=DORMANT_MSG)
         await channel.send(embed=embed)
@@ -637,17 +646,17 @@ class HelpChannels(Scheduler, commands.Cog):
         if self.is_in_category(channel, constants.Categories.help_in_use):
             log.trace(f"Checking if #{channel} ({channel.id}) has been answered.")
 
-            # Check if there is an entry in unanswered (does not persist across restarts)
-            if channel.id in self.unanswered:
-                claimant = self.help_channel_claimants.get(channel)
-                if not claimant:
-                    # The mapping for this channel was lost, we can't do anything.
+            # Check if there is an entry in unanswered
+            if await self.unanswered.contains(channel.id):
+                claimant_id = await self.help_channel_claimants.get(channel.id)
+                if not claimant_id:
+                    # The mapping for this channel doesn't exist, we can't do anything.
                     return
 
                 # Check the message did not come from the claimant
-                if claimant.id != message.author.id:
+                if claimant_id != message.author.id:
                     # Mark the channel as answered
-                    self.unanswered[channel.id] = False
+                    await self.unanswered.set(channel.id, False)
 
     @commands.Cog.listener()
     async def on_message(self, message: discord.Message) -> None:
@@ -680,12 +689,15 @@ class HelpChannels(Scheduler, commands.Cog):
             await self.move_to_in_use(channel)
             await self.revoke_send_permissions(message.author)
             # Add user with channel for dormant check.
-            self.help_channel_claimants[channel] = message.author
+            await self.help_channel_claimants.set(channel.id, message.author.id)
 
             self.bot.stats.incr("help.claimed")
 
-            self.claim_times[channel.id] = datetime.now()
-            self.unanswered[channel.id] = True
+            # Must use a timezone-aware datetime to ensure a correct POSIX timestamp.
+            timestamp = datetime.now(timezone.utc).timestamp()
+            await self.claim_times.set(channel.id, timestamp)
+
+            await self.unanswered.set(channel.id, True)
 
             log.trace(f"Releasing on_message lock for {message.id}.")
 
@@ -720,15 +732,28 @@ class HelpChannels(Scheduler, commands.Cog):
         msg = await self.get_last_message(channel)
         return self.match_bot_embed(msg, AVAILABLE_MSG)
 
-    async def reset_send_permissions(self) -> None:
-        """Reset send permissions in the Available category for claimants."""
-        log.trace("Resetting send permissions in the Available category.")
+    async def check_cooldowns(self) -> None:
+        """Remove expired cooldowns and re-schedule active ones."""
+        log.trace("Checking all cooldowns to remove or re-schedule them.")
         guild = self.bot.get_guild(constants.Guild.id)
+        cooldown = constants.HelpChannels.claim_minutes * 60
+
+        for channel_id, member_id in await self.help_channel_claimants.items():
+            member = guild.get_member(member_id)
+            if not member:
+                continue  # Member probably left the guild.
+
+            in_use_time = await self.get_in_use_time(channel_id)
 
-        # TODO: replace with a persistent cache cause checking every member is quite slow
-        for member in guild.members:
-            if self.is_claimant(member):
+            if not in_use_time or in_use_time.seconds > cooldown:
+                # Remove the role if no claim time could be retrieved or if the cooldown expired.
+                # Since the channel is in the claimants cache, it is definitely strange for a time
+                # to not exist. However, it isn't a reason to keep the user stuck with a cooldown.
                 await self.remove_cooldown_role(member)
+            else:
+                # The member is still on a cooldown; re-schedule it for the remaining time.
+                remaining = cooldown - in_use_time.seconds
+                await self.schedule_cooldown_expiration(member, remaining)
 
     async def add_cooldown_role(self, member: discord.Member) -> None:
         """Add the help cooldown role to `member`."""
@@ -781,11 +806,14 @@ class HelpChannels(Scheduler, commands.Cog):
         # Would mean the user somehow bypassed the lack of permissions (e.g. user is guild owner).
         self.cancel_task(member.id, ignore_missing=True)
 
-        timeout = constants.HelpChannels.claim_minutes * 60
-        callback = self.remove_cooldown_role(member)
+        await self.schedule_cooldown_expiration(member, constants.HelpChannels.claim_minutes * 60)
 
-        log.trace(f"Scheduling {member}'s ({member.id}) send message permissions to be reinstated.")
-        self.schedule_task(member.id, TaskData(timeout, callback))
+    async def schedule_cooldown_expiration(self, member: discord.Member, seconds: int) -> None:
+        """Schedule the cooldown role for `member` to be removed after a duration of `seconds`."""
+        log.trace(f"Scheduling removal of {member}'s ({member.id}) cooldown.")
+
+        callback = self.remove_cooldown_role(member)
+        self.schedule_task(member.id, TaskData(seconds, callback))
 
     async def send_available_message(self, channel: discord.TextChannel) -> None:
         """Send the available message by editing a dormant message or sending a new message."""
diff --git a/bot/cogs/information.py b/bot/cogs/information.py
index f0eb3a1ea..f0bd1afdb 100644
--- a/bot/cogs/information.py
+++ b/bot/cogs/information.py
@@ -6,7 +6,8 @@ from collections import Counter, defaultdict
 from string import Template
 from typing import Any, Mapping, Optional, Union
 
-from discord import Colour, Embed, Member, Message, Role, Status, utils
+from discord import ChannelType, Colour, Embed, Guild, Member, Message, Role, Status, utils
+from discord.abc import GuildChannel
 from discord.ext.commands import BucketType, Cog, Context, Paginator, command, group
 from discord.utils import escape_markdown
 
@@ -26,6 +27,49 @@ class Information(Cog):
     def __init__(self, bot: Bot):
         self.bot = bot
 
+    @staticmethod
+    def role_can_read(channel: GuildChannel, role: Role) -> bool:
+        """Return True if `role` can read messages in `channel`."""
+        overwrites = channel.overwrites_for(role)
+        return overwrites.read_messages is True
+
+    def get_staff_channel_count(self, guild: Guild) -> int:
+        """
+        Get the number of channels that are staff-only.
+
+        We need to know two things about a channel:
+        - Does the @everyone role have explicit read deny permissions?
+        - Do staff roles have explicit read allow permissions?
+
+        If the answer to both of these questions is yes, it's a staff channel.
+        """
+        channel_ids = set()
+        for channel in guild.channels:
+            if channel.type is ChannelType.category:
+                continue
+
+            everyone_can_read = self.role_can_read(channel, guild.default_role)
+
+            for role in constants.STAFF_ROLES:
+                role_can_read = self.role_can_read(channel, guild.get_role(role))
+                if role_can_read and not everyone_can_read:
+                    channel_ids.add(channel.id)
+                    break
+
+        return len(channel_ids)
+
+    @staticmethod
+    def get_channel_type_counts(guild: Guild) -> str:
+        """Return the total amounts of the various types of channels in `guild`."""
+        channel_counter = Counter(c.type for c in guild.channels)
+        channel_type_list = []
+        for channel, count in channel_counter.items():
+            channel_type = str(channel).title()
+            channel_type_list.append(f"{channel_type} channels: {count}")
+
+        channel_type_list = sorted(channel_type_list)
+        return "\n".join(channel_type_list)
+
     @with_role(*constants.MODERATION_ROLES)
     @command(name="roles")
     async def roles_info(self, ctx: Context) -> None:
@@ -102,15 +146,16 @@ class Information(Cog):
 
         roles = len(ctx.guild.roles)
         member_count = ctx.guild.member_count
-
-        # How many of each type of channel?
-        channels = Counter(c.type for c in ctx.guild.channels)
-        channel_counts = "".join(sorted(f"{str(ch).title()} channels: {channels[ch]}\n" for ch in channels)).strip()
+        channel_counts = self.get_channel_type_counts(ctx.guild)
 
         # How many of each user status?
         statuses = Counter(member.status for member in ctx.guild.members)
         embed = Embed(colour=Colour.blurple())
 
+        # How many staff members and staff channels do we have?
+        staff_member_count = len(ctx.guild.get_role(constants.Roles.helpers).members)
+        staff_channel_count = self.get_staff_channel_count(ctx.guild)
+
         # Because channel_counts lacks leading whitespace, it breaks the dedent if it's inserted directly by the
         # f-string. While this is correctly formated by Discord, it makes unit testing difficult. To keep the formatting
         # without joining a tuple of strings we can use a Template string to insert the already-formatted channel_counts
@@ -122,12 +167,16 @@ class Information(Cog):
                 Voice region: {region}
                 Features: {features}
 
-                **Counts**
+                **Channel counts**
+                $channel_counts
+                Staff channels: {staff_channel_count}
+
+                **Member counts**
                 Members: {member_count:,}
+                Staff members: {staff_member_count}
                 Roles: {roles}
-                $channel_counts
 
-                **Members**
+                **Member statuses**
                 {constants.Emojis.status_online} {statuses[Status.online]:,}
                 {constants.Emojis.status_idle} {statuses[Status.idle]:,}
                 {constants.Emojis.status_dnd} {statuses[Status.dnd]:,}
diff --git a/bot/cogs/moderation/infractions.py b/bot/cogs/moderation/infractions.py
index e62a36c43..3b28526b2 100644
--- a/bot/cogs/moderation/infractions.py
+++ b/bot/cogs/moderation/infractions.py
@@ -1,4 +1,5 @@
 import logging
+import textwrap
 import typing as t
 
 import discord
@@ -52,7 +53,7 @@ class Infractions(InfractionScheduler, commands.Cog):
     # region: Permanent infractions
 
     @command()
-    async def warn(self, ctx: Context, user: Member, *, reason: str = None) -> None:
+    async def warn(self, ctx: Context, user: Member, *, reason: t.Optional[str] = None) -> None:
         """Warn a user for the given reason."""
         infraction = await utils.post_infraction(ctx, user, "warning", reason, active=False)
         if infraction is None:
@@ -61,12 +62,12 @@ class Infractions(InfractionScheduler, commands.Cog):
         await self.apply_infraction(ctx, infraction, user)
 
     @command()
-    async def kick(self, ctx: Context, user: Member, *, reason: str = None) -> None:
+    async def kick(self, ctx: Context, user: Member, *, reason: t.Optional[str] = None) -> None:
         """Kick a user for the given reason."""
         await self.apply_kick(ctx, user, reason, active=False)
 
     @command()
-    async def ban(self, ctx: Context, user: FetchedMember, *, reason: str = None) -> None:
+    async def ban(self, ctx: Context, user: FetchedMember, *, reason: t.Optional[str] = None) -> None:
         """Permanently ban a user for the given reason and stop watching them with Big Brother."""
         await self.apply_ban(ctx, user, reason)
 
@@ -74,7 +75,7 @@ class Infractions(InfractionScheduler, commands.Cog):
     # region: Temporary infractions
 
     @command(aliases=["mute"])
-    async def tempmute(self, ctx: Context, user: Member, duration: Expiry, *, reason: str = None) -> None:
+    async def tempmute(self, ctx: Context, user: Member, duration: Expiry, *, reason: t.Optional[str] = None) -> None:
         """
         Temporarily mute a user for the given reason and duration.
 
@@ -93,7 +94,14 @@ class Infractions(InfractionScheduler, commands.Cog):
         await self.apply_mute(ctx, user, reason, expires_at=duration)
 
     @command()
-    async def tempban(self, ctx: Context, user: FetchedMember, duration: Expiry, *, reason: str = None) -> None:
+    async def tempban(
+        self,
+        ctx: Context,
+        user: FetchedMember,
+        duration: Expiry,
+        *,
+        reason: t.Optional[str] = None
+    ) -> None:
         """
         Temporarily ban a user for the given reason and duration.
 
@@ -115,7 +123,7 @@ class Infractions(InfractionScheduler, commands.Cog):
     # region: Permanent shadow infractions
 
     @command(hidden=True)
-    async def note(self, ctx: Context, user: FetchedMember, *, reason: str = None) -> None:
+    async def note(self, ctx: Context, user: FetchedMember, *, reason: t.Optional[str] = None) -> None:
         """Create a private note for a user with the given reason without notifying the user."""
         infraction = await utils.post_infraction(ctx, user, "note", reason, hidden=True, active=False)
         if infraction is None:
@@ -124,12 +132,12 @@ class Infractions(InfractionScheduler, commands.Cog):
         await self.apply_infraction(ctx, infraction, user)
 
     @command(hidden=True, aliases=['shadowkick', 'skick'])
-    async def shadow_kick(self, ctx: Context, user: Member, *, reason: str = None) -> None:
+    async def shadow_kick(self, ctx: Context, user: Member, *, reason: t.Optional[str] = None) -> None:
         """Kick a user for the given reason without notifying the user."""
         await self.apply_kick(ctx, user, reason, hidden=True, active=False)
 
     @command(hidden=True, aliases=['shadowban', 'sban'])
-    async def shadow_ban(self, ctx: Context, user: FetchedMember, *, reason: str = None) -> None:
+    async def shadow_ban(self, ctx: Context, user: FetchedMember, *, reason: t.Optional[str] = None) -> None:
         """Permanently ban a user for the given reason without notifying the user."""
         await self.apply_ban(ctx, user, reason, hidden=True)
 
@@ -137,7 +145,13 @@ class Infractions(InfractionScheduler, commands.Cog):
     # region: Temporary shadow infractions
 
     @command(hidden=True, aliases=["shadowtempmute, stempmute", "shadowmute", "smute"])
-    async def shadow_tempmute(self, ctx: Context, user: Member, duration: Expiry, *, reason: str = None) -> None:
+    async def shadow_tempmute(
+        self, ctx: Context,
+        user: Member,
+        duration: Expiry,
+        *,
+        reason: t.Optional[str] = None
+    ) -> None:
         """
         Temporarily mute a user for the given reason and duration without notifying the user.
 
@@ -162,7 +176,7 @@ class Infractions(InfractionScheduler, commands.Cog):
         user: FetchedMember,
         duration: Expiry,
         *,
-        reason: str = None
+        reason: t.Optional[str] = None
     ) -> None:
         """
         Temporarily ban a user for the given reason and duration without notifying the user.
@@ -197,7 +211,7 @@ class Infractions(InfractionScheduler, commands.Cog):
     # endregion
     # region: Base apply functions
 
-    async def apply_mute(self, ctx: Context, user: Member, reason: str, **kwargs) -> None:
+    async def apply_mute(self, ctx: Context, user: Member, reason: t.Optional[str], **kwargs) -> None:
         """Apply a mute infraction with kwargs passed to `post_infraction`."""
         if await utils.get_active_infraction(ctx, user, "mute"):
             return
@@ -217,7 +231,7 @@ class Infractions(InfractionScheduler, commands.Cog):
         await self.apply_infraction(ctx, infraction, user, action())
 
     @respect_role_hierarchy()
-    async def apply_kick(self, ctx: Context, user: Member, reason: str, **kwargs) -> None:
+    async def apply_kick(self, ctx: Context, user: Member, reason: t.Optional[str], **kwargs) -> None:
         """Apply a kick infraction with kwargs passed to `post_infraction`."""
         infraction = await utils.post_infraction(ctx, user, "kick", reason, active=False, **kwargs)
         if infraction is None:
@@ -225,11 +239,14 @@ class Infractions(InfractionScheduler, commands.Cog):
 
         self.mod_log.ignore(Event.member_remove, user.id)
 
+        if reason:
+            reason = textwrap.shorten(reason, width=512, placeholder="...")
+
         action = user.kick(reason=reason)
         await self.apply_infraction(ctx, infraction, user, action)
 
     @respect_role_hierarchy()
-    async def apply_ban(self, ctx: Context, user: UserSnowflake, reason: str, **kwargs) -> None:
+    async def apply_ban(self, ctx: Context, user: UserSnowflake, reason: t.Optional[str], **kwargs) -> None:
         """
         Apply a ban infraction with kwargs passed to `post_infraction`.
 
@@ -258,6 +275,9 @@ class Infractions(InfractionScheduler, commands.Cog):
 
         self.mod_log.ignore(Event.member_remove, user.id)
 
+        if reason:
+            reason = textwrap.shorten(reason, width=512, placeholder="...")
+
         action = ctx.guild.ban(user, reason=reason, delete_message_days=0)
         await self.apply_infraction(ctx, infraction, user, action)
 
@@ -278,7 +298,7 @@ class Infractions(InfractionScheduler, commands.Cog):
     # endregion
     # region: Base pardon functions
 
-    async def pardon_mute(self, user_id: int, guild: discord.Guild, reason: str) -> t.Dict[str, str]:
+    async def pardon_mute(self, user_id: int, guild: discord.Guild, reason: t.Optional[str]) -> t.Dict[str, str]:
         """Remove a user's muted role, DM them a notification, and return a log dict."""
         user = guild.get_member(user_id)
         log_text = {}
@@ -304,7 +324,7 @@ class Infractions(InfractionScheduler, commands.Cog):
 
         return log_text
 
-    async def pardon_ban(self, user_id: int, guild: discord.Guild, reason: str) -> t.Dict[str, str]:
+    async def pardon_ban(self, user_id: int, guild: discord.Guild, reason: t.Optional[str]) -> t.Dict[str, str]:
         """Remove a user's ban on the Discord guild and return a log dict."""
         user = discord.Object(user_id)
         log_text = {}
diff --git a/bot/cogs/moderation/modlog.py b/bot/cogs/moderation/modlog.py
index beef7a8ef..41472c64c 100644
--- a/bot/cogs/moderation/modlog.py
+++ b/bot/cogs/moderation/modlog.py
@@ -98,7 +98,10 @@ class ModLog(Cog, name="ModLog"):
         footer: t.Optional[str] = None,
     ) -> Context:
         """Generate log embed and send to logging channel."""
-        embed = discord.Embed(description=text)
+        # Truncate string directly here to avoid removing newlines
+        embed = discord.Embed(
+            description=text[:2045] + "..." if len(text) > 2048 else text
+        )
 
         if title and icon_url:
             embed.set_author(name=title, icon_url=icon_url)
@@ -552,6 +555,10 @@ class ModLog(Cog, name="ModLog"):
         channel = message.channel
         author = message.author
 
+        # Ignore DMs.
+        if not message.guild:
+            return
+
         if message.guild.id != GuildConstant.id or channel.id in GuildConstant.modlog_blacklist:
             return
 
diff --git a/bot/cogs/moderation/scheduler.py b/bot/cogs/moderation/scheduler.py
index 012432e60..d75a72ddb 100644
--- a/bot/cogs/moderation/scheduler.py
+++ b/bot/cogs/moderation/scheduler.py
@@ -101,11 +101,16 @@ class InfractionScheduler(Scheduler):
 
         dm_result = ""
         dm_log_text = ""
-        expiry_log_text = f"Expires: {expiry}" if expiry else ""
+        expiry_log_text = f"\nExpires: {expiry}" if expiry else ""
         log_title = "applied"
         log_content = None
+        failed = False
 
         # DM the user about the infraction if it's not a shadow/hidden infraction.
+        # This needs to happen before we apply the infraction, as the bot cannot
+        # send DMs to user that it doesn't share a guild with. If we were to
+        # apply kick/ban infractions first, this would mean that we'd make it
+        # impossible for us to deliver a DM. See python-discord/bot#982.
         if not infraction["hidden"]:
             dm_result = f"{constants.Emojis.failmail} "
             dm_log_text = "\nDM: **Failed**"
@@ -122,18 +127,17 @@ class InfractionScheduler(Scheduler):
                     dm_result = ":incoming_envelope: "
                     dm_log_text = "\nDM: Sent"
 
+        end_msg = ""
         if infraction["actor"] == self.bot.user.id:
             log.trace(
                 f"Infraction #{id_} actor is bot; including the reason in the confirmation message."
             )
-
-            end_msg = f" (reason: {infraction['reason']})"
+            if reason:
+                end_msg = f" (reason: {textwrap.shorten(reason, width=1500, placeholder='...')})"
         elif ctx.channel.id not in STAFF_CHANNELS:
             log.trace(
                 f"Infraction #{id_} context is not in a staff channel; omitting infraction count."
             )
-
-            end_msg = ""
         else:
             log.trace(f"Fetching total infraction count for {user}.")
 
@@ -164,12 +168,23 @@ class InfractionScheduler(Scheduler):
                     log.warning(f"{log_msg}: bot lacks permissions.")
                 else:
                     log.exception(log_msg)
+                failed = True
+
+        if failed:
+            log.trace(f"Deleted infraction {infraction['id']} from database because applying infraction failed.")
+            try:
+                await self.bot.api_client.delete(f"bot/infractions/{id_}")
+            except ResponseCodeError as e:
+                confirm_msg += " and failed to delete"
+                log_title += " and failed to delete"
+                log.error(f"Deletion of {infr_type} infraction #{id_} failed with error code {e.status}.")
+            infr_message = ""
+        else:
+            infr_message = f" **{infr_type}** to {user.mention}{expiry_msg}{end_msg}"
 
         # Send a confirmation message to the invoking context.
         log.trace(f"Sending infraction #{id_} confirmation message.")
-        await ctx.send(
-            f"{dm_result}{confirm_msg} **{infr_type}** to {user.mention}{expiry_msg}{end_msg}."
-        )
+        await ctx.send(f"{dm_result}{confirm_msg}{infr_message}.")
 
         # Send a log message to the mod log.
         log.trace(f"Sending apply mod log for infraction #{id_}.")
@@ -180,9 +195,8 @@ class InfractionScheduler(Scheduler):
             thumbnail=user.avatar_url_as(static_format="png"),
             text=textwrap.dedent(f"""
                 Member: {user.mention} (`{user.id}`)
-                Actor: {ctx.message.author}{dm_log_text}
+                Actor: {ctx.message.author}{dm_log_text}{expiry_log_text}
                 Reason: {reason}
-                {expiry_log_text}
             """),
             content=log_content,
             footer=f"ID {infraction['id']}"
@@ -294,6 +308,9 @@ class InfractionScheduler(Scheduler):
                 f"{log_text.get('Failure', '')}"
             )
 
+        # Move reason to end of entry to avoid cutting out some keys
+        log_text["Reason"] = log_text.pop("Reason")
+
         # Send a log message to the mod log.
         await self.mod_log.send_log_message(
             icon_url=utils.INFRACTION_ICONS[infr_type][1],
@@ -407,6 +424,9 @@ class InfractionScheduler(Scheduler):
             user = self.bot.get_user(user_id)
             avatar = user.avatar_url_as(static_format="png") if user else None
 
+            # Move reason to end so when reason is too long, this is not gonna cut out required items.
+            log_text["Reason"] = log_text.pop("Reason")
+
             log.trace(f"Sending deactivation mod log for infraction #{id_}.")
             await self.mod_log.send_log_message(
                 icon_url=utils.INFRACTION_ICONS[type_][1],
@@ -416,7 +436,6 @@ class InfractionScheduler(Scheduler):
                 text="\n".join(f"{k}: {v}" for k, v in log_text.items()),
                 footer=f"ID: {id_}",
                 content=log_content,
-
             )
 
         return log_text
diff --git a/bot/cogs/moderation/silence.py b/bot/cogs/moderation/silence.py
index 25febfa51..c8ab6443b 100644
--- a/bot/cogs/moderation/silence.py
+++ b/bot/cogs/moderation/silence.py
@@ -1,7 +1,7 @@
 import asyncio
 import logging
 from contextlib import suppress
-from typing import Optional
+from typing import NamedTuple, Optional
 
 from discord import TextChannel
 from discord.ext import commands, tasks
@@ -11,10 +11,18 @@ from bot.bot import Bot
 from bot.constants import Channels, Emojis, Guild, MODERATION_ROLES, Roles
 from bot.converters import HushDurationConverter
 from bot.utils.checks import with_role_check
+from bot.utils.scheduling import Scheduler
 
 log = logging.getLogger(__name__)
 
 
+class TaskData(NamedTuple):
+    """Data for a scheduled task."""
+
+    delay: int
+    ctx: Context
+
+
 class SilenceNotifier(tasks.Loop):
     """Loop notifier for posting notices to `alert_channel` containing added channels."""
 
@@ -53,15 +61,25 @@ class SilenceNotifier(tasks.Loop):
             await self._alert_channel.send(f"<@&{Roles.moderators}> currently silenced channels: {channels_text}")
 
 
-class Silence(commands.Cog):
+class Silence(Scheduler, commands.Cog):
     """Commands for stopping channel messages for `verified` role in a channel."""
 
     def __init__(self, bot: Bot):
+        super().__init__()
         self.bot = bot
         self.muted_channels = set()
         self._get_instance_vars_task = self.bot.loop.create_task(self._get_instance_vars())
         self._get_instance_vars_event = asyncio.Event()
 
+    async def _scheduled_task(self, task: TaskData) -> None:
+        """Calls `self.unsilence` on expired silenced channel to unsilence it."""
+        await asyncio.sleep(task.delay)
+        log.info("Unsilencing channel after set delay.")
+
+        # Because `self.unsilence` explicitly cancels this scheduled task, it is shielded
+        # to avoid prematurely cancelling itself
+        await asyncio.shield(task.ctx.invoke(self.unsilence))
+
     async def _get_instance_vars(self) -> None:
         """Get instance variables after they're available to get from the guild."""
         await self.bot.wait_until_guild_available()
@@ -90,9 +108,13 @@ class Silence(commands.Cog):
             return
 
         await ctx.send(f"{Emojis.check_mark} silenced current channel for {duration} minute(s).")
-        await asyncio.sleep(duration*60)
-        log.info("Unsilencing channel after set delay.")
-        await ctx.invoke(self.unsilence)
+
+        task_data = TaskData(
+            delay=duration*60,
+            ctx=ctx
+        )
+
+        self.schedule_task(ctx.channel.id, task_data)
 
     @commands.command(aliases=("unhush",))
     async def unsilence(self, ctx: Context) -> None:
@@ -103,7 +125,9 @@ class Silence(commands.Cog):
         """
         await self._get_instance_vars_event.wait()
         log.debug(f"Unsilencing channel #{ctx.channel} from {ctx.author}'s command.")
-        if await self._unsilence(ctx.channel):
+        if not await self._unsilence(ctx.channel):
+            await ctx.send(f"{Emojis.cross_mark} current channel was not silenced.")
+        else:
             await ctx.send(f"{Emojis.check_mark} unsilenced current channel.")
 
     async def _silence(self, channel: TextChannel, persistent: bool, duration: Optional[int]) -> bool:
@@ -140,6 +164,7 @@ class Silence(commands.Cog):
         if current_overwrite.send_messages is False:
             await channel.set_permissions(self._verified_role, **dict(current_overwrite, send_messages=None))
             log.info(f"Unsilenced channel #{channel} ({channel.id}).")
+            self.cancel_task(channel.id)
             self.notifier.remove_channel(channel)
             self.muted_channels.discard(channel)
             return True
diff --git a/bot/cogs/moderation/superstarify.py b/bot/cogs/moderation/superstarify.py
index 29855c325..45a010f00 100644
--- a/bot/cogs/moderation/superstarify.py
+++ b/bot/cogs/moderation/superstarify.py
@@ -183,10 +183,10 @@ class Superstarify(InfractionScheduler, Cog):
             text=textwrap.dedent(f"""
                 Member: {member.mention} (`{member.id}`)
                 Actor: {ctx.message.author}
-                Reason: {reason}
                 Expires: {expiry_str}
                 Old nickname: `{old_nick}`
                 New nickname: `{forced_nick}`
+                Reason: {reason}
             """),
             footer=f"ID {id_}"
         )
diff --git a/bot/cogs/moderation/utils.py b/bot/cogs/moderation/utils.py
index e4e0f1ec2..fb55287b6 100644
--- a/bot/cogs/moderation/utils.py
+++ b/bot/cogs/moderation/utils.py
@@ -41,7 +41,6 @@ async def post_user(ctx: Context, user: UserSnowflake) -> t.Optional[dict]:
         log.debug("The user being added to the DB is not a Member or User object.")
 
     payload = {
-        'avatar_hash': getattr(user, 'avatar', 0),
         'discriminator': int(getattr(user, 'discriminator', 0)),
         'id': user.id,
         'in_guild': False,
@@ -143,12 +142,14 @@ async def notify_infraction(
     """DM a user about their new infraction and return True if the DM is successful."""
     log.trace(f"Sending {user} a DM about their {infr_type} infraction.")
 
+    text = textwrap.dedent(f"""
+        **Type:** {infr_type.capitalize()}
+        **Expires:** {expires_at or "N/A"}
+        **Reason:** {reason or "No reason provided."}
+    """)
+
     embed = discord.Embed(
-        description=textwrap.dedent(f"""
-            **Type:** {infr_type.capitalize()}
-            **Expires:** {expires_at or "N/A"}
-            **Reason:** {reason or "No reason provided."}
-            """),
+        description=textwrap.shorten(text, width=2048, placeholder="..."),
         colour=Colours.soft_red
     )
 
diff --git a/bot/cogs/python_news.py b/bot/cogs/python_news.py
index d15d0371e..adefd5c7c 100644
--- a/bot/cogs/python_news.py
+++ b/bot/cogs/python_news.py
@@ -10,6 +10,7 @@ from discord.ext.tasks import loop
 
 from bot import constants
 from bot.bot import Bot
+from bot.utils.messages import sub_clyde
 
 PEPS_RSS_URL = "https://www.python.org/dev/peps/peps.rss/"
 
@@ -208,7 +209,7 @@ class PythonNews(Cog):
 
         return await self.webhook.send(
             embed=embed,
-            username=webhook_profile_name,
+            username=sub_clyde(webhook_profile_name),
             avatar_url=AVATAR_URL,
             wait=True
         )
diff --git a/bot/cogs/reddit.py b/bot/cogs/reddit.py
index 3b77538a0..d853ab2ea 100644
--- a/bot/cogs/reddit.py
+++ b/bot/cogs/reddit.py
@@ -16,6 +16,7 @@ from bot.constants import Channels, ERROR_REPLIES, Emojis, Reddit as RedditConfi
 from bot.converters import Subreddit
 from bot.decorators import with_role
 from bot.pagination import LinePaginator
+from bot.utils.messages import sub_clyde
 
 log = logging.getLogger(__name__)
 
@@ -218,7 +219,8 @@ class Reddit(Cog):
 
         for subreddit in RedditConfig.subreddits:
             top_posts = await self.get_top_posts(subreddit=subreddit, time="day")
-            message = await self.webhook.send(username=f"{subreddit} Top Daily Posts", embed=top_posts, wait=True)
+            username = sub_clyde(f"{subreddit} Top Daily Posts")
+            message = await self.webhook.send(username=username, embed=top_posts, wait=True)
 
             if message.channel.is_news():
                 await message.publish()
@@ -228,8 +230,8 @@ class Reddit(Cog):
         for subreddit in RedditConfig.subreddits:
             # Send and pin the new weekly posts.
             top_posts = await self.get_top_posts(subreddit=subreddit, time="week")
-
-            message = await self.webhook.send(wait=True, username=f"{subreddit} Top Weekly Posts", embed=top_posts)
+            username = sub_clyde(f"{subreddit} Top Weekly Posts")
+            message = await self.webhook.send(wait=True, username=username, embed=top_posts)
 
             if subreddit.lower() == "r/python":
                 if not self.channel:
diff --git a/bot/cogs/site.py b/bot/cogs/site.py
index 7fc2a9c34..ac29daa1d 100644
--- a/bot/cogs/site.py
+++ b/bot/cogs/site.py
@@ -33,7 +33,7 @@ class Site(Cog):
         embed.colour = Colour.blurple()
         embed.description = (
             f"[Our official website]({url}) is an open-source community project "
-            "created with Python and Flask. It contains information about the server "
+            "created with Python and Django. It contains information about the server "
             "itself, lets you sign up for upcoming events, has its own wiki, contains "
             "a list of valuable learning resources, and much more."
         )
@@ -133,6 +133,9 @@ class Site(Cog):
             await ctx.send(f":x: Invalid rule indices: {indices}")
             return
 
+        for rule in rules:
+            self.bot.stats.incr(f"rule_uses.{rule}")
+
         final_rules = tuple(f"**{pick}.** {full_rules[pick - 1]}" for pick in rules)
 
         await LinePaginator.paginate(final_rules, ctx, rules_embed, max_lines=3)
diff --git a/bot/cogs/stats.py b/bot/cogs/stats.py
index 4ebb6423c..d42f55466 100644
--- a/bot/cogs/stats.py
+++ b/bot/cogs/stats.py
@@ -36,7 +36,8 @@ class Stats(Cog):
         if message.guild.id != Guild.id:
             return
 
-        if message.channel.category.id == Categories.modmail:
+        cat = getattr(message.channel, "category", None)
+        if cat is not None and cat.id == Categories.modmail:
             if message.channel.id != Channels.incidents:
                 # Do not report modmail channels to stats, there are too many
                 # of them for interesting statistics to be drawn out of this.
diff --git a/bot/cogs/sync/cog.py b/bot/cogs/sync/cog.py
index 5708be3f4..7cc3726b2 100644
--- a/bot/cogs/sync/cog.py
+++ b/bot/cogs/sync/cog.py
@@ -94,7 +94,6 @@ class Sync(Cog):
         the database, the user is added.
         """
         packed = {
-            'avatar_hash': member.avatar,
             'discriminator': int(member.discriminator),
             'id': member.id,
             'in_guild': True,
@@ -135,12 +134,11 @@ class Sync(Cog):
     @Cog.listener()
     async def on_user_update(self, before: User, after: User) -> None:
         """Update the user information in the database if a relevant change is detected."""
-        attrs = ("name", "discriminator", "avatar")
+        attrs = ("name", "discriminator")
         if any(getattr(before, attr) != getattr(after, attr) for attr in attrs):
             updated_information = {
                 "name": after.name,
                 "discriminator": int(after.discriminator),
-                "avatar_hash": after.avatar,
             }
             await self.patch_user(after.id, updated_information=updated_information)
 
diff --git a/bot/cogs/sync/syncers.py b/bot/cogs/sync/syncers.py
index e55bf27fd..536455668 100644
--- a/bot/cogs/sync/syncers.py
+++ b/bot/cogs/sync/syncers.py
@@ -17,7 +17,7 @@ log = logging.getLogger(__name__)
 # These objects are declared as namedtuples because tuples are hashable,
 # something that we make use of when diffing site roles against guild roles.
 _Role = namedtuple('Role', ('id', 'name', 'colour', 'permissions', 'position'))
-_User = namedtuple('User', ('id', 'name', 'discriminator', 'avatar_hash', 'roles', 'in_guild'))
+_User = namedtuple('User', ('id', 'name', 'discriminator', 'roles', 'in_guild'))
 _Diff = namedtuple('Diff', ('created', 'updated', 'deleted'))
 
 
@@ -298,7 +298,6 @@ class UserSyncer(Syncer):
                 id=member.id,
                 name=member.name,
                 discriminator=int(member.discriminator),
-                avatar_hash=member.avatar,
                 roles=tuple(sorted(role.id for role in member.roles)),
                 in_guild=True
             )
diff --git a/bot/cogs/tags.py b/bot/cogs/tags.py
index bc7f53f68..6f03a3475 100644
--- a/bot/cogs/tags.py
+++ b/bot/cogs/tags.py
@@ -44,7 +44,7 @@ class Tags(Cog):
                 tag = {
                     "title": tag_title,
                     "embed": {
-                        "description": file.read_text(),
+                        "description": file.read_text(encoding="utf8"),
                     },
                     "restricted_to": "developers",
                 }
diff --git a/bot/cogs/token_remover.py b/bot/cogs/token_remover.py
index 6721f0e02..ef979f222 100644
--- a/bot/cogs/token_remover.py
+++ b/bot/cogs/token_remover.py
@@ -2,20 +2,22 @@ import base64
 import binascii
 import logging
 import re
-import struct
 import typing as t
-from datetime import datetime
 
-from discord import Colour, Message
+from discord import Colour, Message, NotFound
 from discord.ext.commands import Cog
-from discord.utils import snowflake_time
 
+from bot import utils
 from bot.bot import Bot
 from bot.cogs.moderation import ModLog
 from bot.constants import Channels, Colours, Event, Icons
 
 log = logging.getLogger(__name__)
 
+LOG_MESSAGE = (
+    "Censored a seemingly valid token sent by {author} (`{author_id}`) in {channel}, "
+    "token was `{user_id}.{timestamp}.{hmac}`"
+)
 DELETION_MESSAGE_TEMPLATE = (
     "Hey {mention}! I noticed you posted a seemingly valid Discord API "
     "token in your message and have removed your message. "
@@ -25,15 +27,22 @@ DELETION_MESSAGE_TEMPLATE = (
     "Feel free to re-post it with the token removed. "
     "If you believe this was a mistake, please let us know!"
 )
-DISCORD_EPOCH_TIMESTAMP = datetime(2017, 1, 1)
+DISCORD_EPOCH = 1_420_070_400
 TOKEN_EPOCH = 1_293_840_000
-TOKEN_RE = re.compile(
-    r"[^\s\.()\"']+"  # Matches token part 1: The user ID string, encoded as base64
-    r"\."             # Matches a literal dot between the token parts
-    r"[^\s\.()\"']+"  # Matches token part 2: The creation timestamp, as an integer
-    r"\."             # Matches a literal dot between the token parts
-    r"[^\s\.()\"']+"  # Matches token part 3: The HMAC, unused by us, but check that it isn't empty
-)
+
+# Three parts delimited by dots: user ID, creation timestamp, HMAC.
+# The HMAC isn't parsed further, but it's in the regex to ensure it at least exists in the string.
+# Each part only matches base64 URL-safe characters.
+# Padding has never been observed, but the padding character '=' is matched just in case.
+TOKEN_RE = re.compile(r"([\w\-=]+)\.([\w\-=]+)\.([\w\-=]+)", re.ASCII)
+
+
+class Token(t.NamedTuple):
+    """A Discord Bot token."""
+
+    user_id: str
+    timestamp: str
+    hmac: str
 
 
 class TokenRemover(Cog):
@@ -54,6 +63,10 @@ class TokenRemover(Cog):
 
         See: https://discordapp.com/developers/docs/reference#snowflakes
         """
+        # Ignore DMs; can't delete messages in there anyway.
+        if not msg.guild or msg.author.bot:
+            return
+
         found_token = self.find_token_in_message(msg)
         if found_token:
             await self.take_action(msg, found_token)
@@ -65,64 +78,61 @@ class TokenRemover(Cog):
 
         See: https://discordapp.com/developers/docs/reference#snowflakes
         """
-        found_token = self.find_token_in_message(after)
-        if found_token:
-            await self.take_action(after, found_token)
+        await self.on_message(after)
 
-    async def take_action(self, msg: Message, found_token: str) -> None:
-        """Remove the `msg` containing a token an send a mod_log message."""
-        user_id, creation_timestamp, hmac = found_token.split('.')
+    async def take_action(self, msg: Message, found_token: Token) -> None:
+        """Remove the `msg` containing the `found_token` and send a mod log message."""
         self.mod_log.ignore(Event.message_delete, msg.id)
-        await msg.delete()
+
+        try:
+            await msg.delete()
+        except NotFound:
+            log.debug(f"Failed to remove token in message {msg.id}: message already deleted.")
+            return
+
         await msg.channel.send(DELETION_MESSAGE_TEMPLATE.format(mention=msg.author.mention))
 
-        message = (
-            "Censored a seemingly valid token sent by "
-            f"{msg.author} (`{msg.author.id}`) in {msg.channel.mention}, token was "
-            f"`{user_id}.{creation_timestamp}.{'x' * len(hmac)}`"
-        )
-        log.debug(message)
+        log_message = self.format_log_message(msg, found_token)
+        log.debug(log_message)
 
         # Send pretty mod log embed to mod-alerts
         await self.mod_log.send_log_message(
             icon_url=Icons.token_removed,
             colour=Colour(Colours.soft_red),
             title="Token removed!",
-            text=message,
+            text=log_message,
             thumbnail=msg.author.avatar_url_as(static_format="png"),
             channel_id=Channels.mod_alerts,
         )
 
         self.bot.stats.incr("tokens.removed_tokens")
 
+    @staticmethod
+    def format_log_message(msg: Message, token: Token) -> str:
+        """Return the log message to send for `token` being censored in `msg`."""
+        return LOG_MESSAGE.format(
+            author=msg.author,
+            author_id=msg.author.id,
+            channel=msg.channel.mention,
+            user_id=token.user_id,
+            timestamp=token.timestamp,
+            hmac='x' * len(token.hmac),
+        )
+
     @classmethod
-    def find_token_in_message(cls, msg: Message) -> t.Optional[str]:
+    def find_token_in_message(cls, msg: Message) -> t.Optional[Token]:
         """Return a seemingly valid token found in `msg` or `None` if no token is found."""
-        if msg.author.bot:
-            return
-
-        # Use findall rather than search to guard against method calls prematurely returning the
+        # Use finditer rather than search to guard against method calls prematurely returning the
         # token check (e.g. `message.channel.send` also matches our token pattern)
-        maybe_matches = TOKEN_RE.findall(msg.content)
-        for substr in maybe_matches:
-            if cls.is_maybe_token(substr):
+        for match in TOKEN_RE.finditer(msg.content):
+            token = Token(*match.groups())
+            if cls.is_valid_user_id(token.user_id) and cls.is_valid_timestamp(token.timestamp):
                 # Short-circuit on first match
-                return substr
+                return token
 
         # No matching substring
         return
 
-    @classmethod
-    def is_maybe_token(cls, test_str: str) -> bool:
-        """Check the provided string to see if it is a seemingly valid token."""
-        try:
-            user_id, creation_timestamp, hmac = test_str.split('.')
-        except ValueError:
-            return False
-
-        if cls.is_valid_user_id(user_id) and cls.is_valid_timestamp(creation_timestamp):
-            return True
-
     @staticmethod
     def is_valid_user_id(b64_content: str) -> bool:
         """
@@ -130,29 +140,41 @@ class TokenRemover(Cog):
 
         See: https://discordapp.com/developers/docs/reference#snowflakes
         """
-        b64_content += '=' * (-len(b64_content) % 4)
+        b64_content = utils.pad_base64(b64_content)
 
         try:
-            content: bytes = base64.b64decode(b64_content)
-            return content.decode('utf-8').isnumeric()
-        except (binascii.Error, UnicodeDecodeError):
+            decoded_bytes = base64.urlsafe_b64decode(b64_content)
+            string = decoded_bytes.decode('utf-8')
+
+            # isdigit on its own would match a lot of other Unicode characters, hence the isascii.
+            return string.isascii() and string.isdigit()
+        except (binascii.Error, ValueError):
             return False
 
     @staticmethod
     def is_valid_timestamp(b64_content: str) -> bool:
         """
-        Check potential token to see if it contains a valid timestamp.
+        Return True if `b64_content` decodes to a valid timestamp.
 
-        See: https://discordapp.com/developers/docs/reference#snowflakes
+        If the timestamp is greater than the Discord epoch, it's probably valid.
+        See: https://i.imgur.com/7WdehGn.png
         """
-        b64_content += '=' * (-len(b64_content) % 4)
+        b64_content = utils.pad_base64(b64_content)
 
         try:
-            content = base64.urlsafe_b64decode(b64_content)
-            snowflake = struct.unpack('i', content)[0]
-        except (binascii.Error, struct.error):
+            decoded_bytes = base64.urlsafe_b64decode(b64_content)
+            timestamp = int.from_bytes(decoded_bytes, byteorder="big")
+        except (binascii.Error, ValueError) as e:
+            log.debug(f"Failed to decode token timestamp '{b64_content}': {e}")
+            return False
+
+        # Seems like newer tokens don't need the epoch added, but add anyway since an upper bound
+        # is not checked.
+        if timestamp + TOKEN_EPOCH >= DISCORD_EPOCH:
+            return True
+        else:
+            log.debug(f"Invalid token timestamp '{b64_content}': smaller than Discord epoch")
             return False
-        return snowflake_time(snowflake + TOKEN_EPOCH) < DISCORD_EPOCH_TIMESTAMP
 
 
 def setup(bot: Bot) -> None:
diff --git a/bot/cogs/utils.py b/bot/cogs/utils.py
index 73b4a1c0a..697bf60ce 100644
--- a/bot/cogs/utils.py
+++ b/bot/cogs/utils.py
@@ -6,7 +6,7 @@ from email.parser import HeaderParser
 from io import StringIO
 from typing import Tuple, Union
 
-from discord import Colour, Embed
+from discord import Colour, Embed, utils
 from discord.ext.commands import BadArgument, Cog, Context, command
 
 from bot.bot import Bot
@@ -145,7 +145,7 @@ class Utils(Cog):
                 u_code = f"\\U{digit:>08}"
             url = f"https://www.compart.com/en/unicode/U+{digit:>04}"
             name = f"[{unicodedata.name(char, '')}]({url})"
-            info = f"`{u_code.ljust(10)}`: {name} - {char}"
+            info = f"`{u_code.ljust(10)}`: {name} - {utils.escape_markdown(char)}"
             return info, u_code
 
         charlist, rawlist = zip(*(get_info(c) for c in characters))
diff --git a/bot/cogs/verification.py b/bot/cogs/verification.py
index 99be3cdaa..ae156cf70 100644
--- a/bot/cogs/verification.py
+++ b/bot/cogs/verification.py
@@ -1,9 +1,7 @@
 import logging
 from contextlib import suppress
-from datetime import datetime
 
 from discord import Colour, Forbidden, Message, NotFound, Object
-from discord.ext import tasks
 from discord.ext.commands import Cog, Context, command
 
 from bot import constants
@@ -34,14 +32,6 @@ If you'd like to unsubscribe from the announcement notifications, simply send `!
 <#{constants.Channels.bot_commands}>.
 """
 
-if constants.DEBUG_MODE:
-    PERIODIC_PING = "Periodic checkpoint message successfully sent."
-else:
-    PERIODIC_PING = (
-        f"@everyone To verify that you have read our rules, please type `{constants.Bot.prefix}accept`."
-        " If you encounter any problems during the verification process, "
-        f"send a direct message to a staff member."
-    )
 BOT_MESSAGE_DELETE_DELAY = 10
 
 
@@ -50,7 +40,6 @@ class Verification(Cog):
 
     def __init__(self, bot: Bot):
         self.bot = bot
-        self.periodic_ping.start()
 
     @property
     def mod_log(self) -> ModLog:
@@ -65,9 +54,7 @@ class Verification(Cog):
 
         if message.author.bot:
             # They're a bot, delete their message after the delay.
-            # But not the periodic ping; we like that one.
-            if message.content != PERIODIC_PING:
-                await message.delete(delay=BOT_MESSAGE_DELETE_DELAY)
+            await message.delete(delay=BOT_MESSAGE_DELETE_DELAY)
             return
 
         # if a user mentions a role or guild member
@@ -198,34 +185,6 @@ class Verification(Cog):
         else:
             return True
 
-    @tasks.loop(hours=12)
-    async def periodic_ping(self) -> None:
-        """Every week, mention @everyone to remind them to verify."""
-        messages = self.bot.get_channel(constants.Channels.verification).history(limit=10)
-        need_to_post = True  # True if a new message needs to be sent.
-
-        async for message in messages:
-            if message.author == self.bot.user and message.content == PERIODIC_PING:
-                delta = datetime.utcnow() - message.created_at  # Time since last message.
-                if delta.days >= 7:  # Message is older than a week.
-                    await message.delete()
-                else:
-                    need_to_post = False
-
-                break
-
-        if need_to_post:
-            await self.bot.get_channel(constants.Channels.verification).send(PERIODIC_PING)
-
-    @periodic_ping.before_loop
-    async def before_ping(self) -> None:
-        """Only start the loop when the bot is ready."""
-        await self.bot.wait_until_guild_available()
-
-    def cog_unload(self) -> None:
-        """Cancel the periodic ping task when the cog is unloaded."""
-        self.periodic_ping.cancel()
-
 
 def setup(bot: Bot) -> None:
     """Load the Verification cog."""
diff --git a/bot/cogs/watchchannels/bigbrother.py b/bot/cogs/watchchannels/bigbrother.py
index e4fb173e0..702d371f4 100644
--- a/bot/cogs/watchchannels/bigbrother.py
+++ b/bot/cogs/watchchannels/bigbrother.py
@@ -1,4 +1,5 @@
 import logging
+import textwrap
 from collections import ChainMap
 
 from discord.ext.commands import Cog, Context, group
@@ -97,8 +98,8 @@ class BigBrother(WatchChannel, Cog, name="Big Brother"):
 
             if len(history) > 1:
                 total = f"({len(history) // 2} previous infractions in total)"
-                end_reason = history[0]["reason"]
-                start_reason = f"Watched: {history[1]['reason']}"
+                end_reason = textwrap.shorten(history[0]["reason"], width=500, placeholder="...")
+                start_reason = f"Watched: {textwrap.shorten(history[1]['reason'], width=500, placeholder='...')}"
                 msg += f"\n\nUser's previous watch reasons {total}:```{start_reason}\n\n{end_reason}```"
         else:
             msg = ":x: Failed to post the infraction: response was empty."
diff --git a/bot/cogs/watchchannels/talentpool.py b/bot/cogs/watchchannels/talentpool.py
index cd9c7e555..14547105f 100644
--- a/bot/cogs/watchchannels/talentpool.py
+++ b/bot/cogs/watchchannels/talentpool.py
@@ -106,8 +106,8 @@ class TalentPool(WatchChannel, Cog, name="Talentpool"):
 
         if history:
             total = f"({len(history)} previous nominations in total)"
-            start_reason = f"Watched: {history[0]['reason']}"
-            end_reason = f"Unwatched: {history[0]['end_reason']}"
+            start_reason = f"Watched: {textwrap.shorten(history[0]['reason'], width=500, placeholder='...')}"
+            end_reason = f"Unwatched: {textwrap.shorten(history[0]['end_reason'], width=500, placeholder='...')}"
             msg += f"\n\nUser's previous watch reasons {total}:```{start_reason}\n\n{end_reason}```"
 
         await ctx.send(msg)
@@ -224,7 +224,7 @@ class TalentPool(WatchChannel, Cog, name="Talentpool"):
                 Status: **Active**
                 Date: {start_date}
                 Actor: {actor.mention if actor else actor_id}
-                Reason: {nomination_object["reason"]}
+                Reason: {textwrap.shorten(nomination_object["reason"], width=200, placeholder="...")}
                 Nomination ID: `{nomination_object["id"]}`
                 ===============
                 """
@@ -237,10 +237,10 @@ class TalentPool(WatchChannel, Cog, name="Talentpool"):
                 Status: Inactive
                 Date: {start_date}
                 Actor: {actor.mention if actor else actor_id}
-                Reason: {nomination_object["reason"]}
+                Reason: {textwrap.shorten(nomination_object["reason"], width=200, placeholder="...")}
 
                 End date: {end_date}
-                Unwatch reason: {nomination_object["end_reason"]}
+                Unwatch reason: {textwrap.shorten(nomination_object["end_reason"], width=200, placeholder="...")}
                 Nomination ID: `{nomination_object["id"]}`
                 ===============
                 """
diff --git a/bot/cogs/watchchannels/watchchannel.py b/bot/cogs/watchchannels/watchchannel.py
index 643cd46e4..7c58a0fb5 100644
--- a/bot/cogs/watchchannels/watchchannel.py
+++ b/bot/cogs/watchchannels/watchchannel.py
@@ -204,6 +204,7 @@ class WatchChannel(metaclass=CogABCMeta):
         embed: Optional[Embed] = None,
     ) -> None:
         """Sends a message to the webhook with the specified kwargs."""
+        username = messages.sub_clyde(username)
         try:
             await self.webhook.send(content=content, username=username, avatar_url=avatar_url, embed=embed)
         except discord.HTTPException as exc:
@@ -280,8 +281,9 @@ class WatchChannel(metaclass=CogABCMeta):
         else:
             message_jump = f"in [#{msg.channel.name}]({msg.jump_url})"
 
+        footer = f"Added {time_delta} by {actor} | Reason: {reason}"
         embed = Embed(description=f"{msg.author.mention} {message_jump}")
-        embed.set_footer(text=f"Added {time_delta} by {actor} | Reason: {reason}")
+        embed.set_footer(text=textwrap.shorten(footer, width=128, placeholder="..."))
 
         await self.webhook_send(embed=embed, username=msg.author.display_name, avatar_url=msg.author.avatar_url)
 
diff --git a/bot/cogs/webhook_remover.py b/bot/cogs/webhook_remover.py
index 1b5c3f821..543869215 100644
--- a/bot/cogs/webhook_remover.py
+++ b/bot/cogs/webhook_remover.py
@@ -1,7 +1,7 @@
 import logging
 import re
 
-from discord import Colour, Message
+from discord import Colour, Message, NotFound
 from discord.ext.commands import Cog
 
 from bot.bot import Bot
@@ -35,7 +35,13 @@ class WebhookRemover(Cog):
         """Delete `msg` and send a warning that it contained the Discord webhook `redacted_url`."""
         # Don't log this, due internal delete, not by user. Will make different entry.
         self.mod_log.ignore(Event.message_delete, msg.id)
-        await msg.delete()
+
+        try:
+            await msg.delete()
+        except NotFound:
+            log.debug(f"Failed to remove webhook in message {msg.id}: message already deleted.")
+            return
+
         await msg.channel.send(ALERT_MESSAGE_TEMPLATE.format(user=msg.author.mention))
 
         message = (
@@ -59,6 +65,10 @@ class WebhookRemover(Cog):
     @Cog.listener()
     async def on_message(self, msg: Message) -> None:
         """Check if a Discord webhook URL is in `message`."""
+        # Ignore DMs; can't delete messages in there anyway.
+        if not msg.guild or msg.author.bot:
+            return
+
         matches = WEBHOOK_URL_RE.search(msg.content)
         if matches:
             await self.delete_and_respond(msg, matches[1] + "xxx")
diff --git a/bot/constants.py b/bot/constants.py
index b31a9c99e..a1b392c82 100644
--- a/bot/constants.py
+++ b/bot/constants.py
@@ -226,6 +226,7 @@ class Filter(metaclass=YAMLGetter):
     notify_user_domains: bool
 
     ping_everyone: bool
+    offensive_msg_delete_days: int
     guild_invite_whitelist: List[int]
     domain_blacklist: List[str]
     word_watchlist: List[str]
@@ -389,6 +390,7 @@ class Channels(metaclass=YAMLGetter):
     attachment_log: int
     big_brother_logs: int
     bot_commands: int
+    cooldown: int
     defcon: int
     dev_contrib: int
     dev_core: int
diff --git a/bot/converters.py b/bot/converters.py
index 72c46fdf0..4deb59f87 100644
--- a/bot/converters.py
+++ b/bot/converters.py
@@ -217,7 +217,10 @@ class Duration(Converter):
         delta = relativedelta(**duration_dict)
         now = datetime.utcnow()
 
-        return now + delta
+        try:
+            return now + delta
+        except ValueError:
+            raise BadArgument(f"`{duration}` results in a datetime outside the supported range.")
 
 
 class ISODateTime(Converter):
diff --git a/bot/resources/tags/customcooldown.md b/bot/resources/tags/customcooldown.md
new file mode 100644
index 000000000..ac7e70aee
--- /dev/null
+++ b/bot/resources/tags/customcooldown.md
@@ -0,0 +1,20 @@
+**Cooldowns in discord.py**
+
+Cooldowns can be used in discord.py to rate-limit. In this example, we're using it in an on_message.
+
+```python
+from discord.ext import commands
+
+message_cooldown = commands.CooldownMapping.from_cooldown(1.0, 60.0, commands.BucketType.user)
+
[email protected]
+async def on_message(message):
+    bucket = message_cooldown.get_bucket(message)
+    retry_after = bucket.update_rate_limit()
+    if retry_after:
+        await message.channel.send(f"Slow down! Try again in {retry_after} seconds.")
+    else:
+        await message.channel.send("Not ratelimited!")
+```
+
+`from_cooldown` takes the amount of `update_rate_limit()`s needed to trigger the cooldown, the time in which the cooldown is triggered, and a [`BucketType`](https://discordpy.readthedocs.io/en/latest/ext/commands/api.html#discord.discord.ext.commands.BucketType).
diff --git a/bot/resources/tags/free.md b/bot/resources/tags/free.md
index 582cca9da..1493076c7 100644
--- a/bot/resources/tags/free.md
+++ b/bot/resources/tags/free.md
@@ -1,5 +1,5 @@
 **We have a new help channel system!**
 
-We recently moved to a new help channel system. You can now use any channel in the **<#691405807388196926>** category to ask your question.
+Please see <#704250143020417084> for further information.
 
-For more information, check out [our website](https://pythondiscord.com/pages/resources/guides/help-channels/).
+A more detailed guide can be found on [our website](https://pythondiscord.com/pages/resources/guides/help-channels/).
diff --git a/bot/resources/tags/modmail.md b/bot/resources/tags/modmail.md
new file mode 100644
index 000000000..7545419ee
--- /dev/null
+++ b/bot/resources/tags/modmail.md
@@ -0,0 +1,9 @@
+**Contacting the moderation team via ModMail**
+
+<@!683001325440860340> is a bot that will relay your messages to our moderation team, so that you can start a conversation with the moderation team. Your messages will be relayed to the entire moderator team, who will be able to respond to you via the bot.
+
+It supports attachments, codeblocks, and reactions. As communication happens over direct messages, the conversation will stay between you and the mod team.
+
+**To use it, simply send a direct message to the bot.**
+
+Should there be an urgent and immediate need for a moderator or admin to look at a channel, feel free to ping the <@&267629731250176001> or <@&267628507062992896> role instead.
diff --git a/bot/utils/__init__.py b/bot/utils/__init__.py
index ac878c356..2c8d57bd5 100644
--- a/bot/utils/__init__.py
+++ b/bot/utils/__init__.py
@@ -64,3 +64,8 @@ async def send_to_paste_service(http_session: ClientSession, contents: str, *, e
             f"Got unexpected JSON response from paste service: {response_json}\n"
             f"trying again ({attempt}/{FAILED_REQUEST_ATTEMPTS})."
         )
+
+
+def pad_base64(data: str) -> str:
+    """Return base64 `data` with padding characters to ensure its length is a multiple of 4."""
+    return data + "=" * (-len(data) % 4)
diff --git a/bot/utils/messages.py b/bot/utils/messages.py
index de8e186f3..a40a12e98 100644
--- a/bot/utils/messages.py
+++ b/bot/utils/messages.py
@@ -1,6 +1,7 @@
 import asyncio
 import contextlib
 import logging
+import re
 from io import BytesIO
 from typing import List, Optional, Sequence, Union
 
@@ -86,7 +87,7 @@ async def send_attachments(
                     else:
                         await destination.send(
                             file=attachment_file,
-                            username=message.author.display_name,
+                            username=sub_clyde(message.author.display_name),
                             avatar_url=message.author.avatar_url
                         )
             elif link_large:
@@ -97,7 +98,7 @@ async def send_attachments(
             if link_large and e.status == 413:
                 large.append(attachment)
             else:
-                log.warning(f"{failure_msg} with status {e.status}.")
+                log.warning(f"{failure_msg} with status {e.status}.", exc_info=e)
 
     if link_large and large:
         desc = "\n".join(f"[{attachment.filename}]({attachment.url})" for attachment in large)
@@ -109,8 +110,25 @@ async def send_attachments(
         else:
             await destination.send(
                 embed=embed,
-                username=message.author.display_name,
+                username=sub_clyde(message.author.display_name),
                 avatar_url=message.author.avatar_url
             )
 
     return urls
+
+
+def sub_clyde(username: Optional[str]) -> Optional[str]:
+    """
+    Replace "e"/"E" in any "clyde" in `username` with a Cyrillic "е"/"E" and return the new string.
+
+    Discord disallows "clyde" anywhere in the username for webhooks. It will return a 400.
+    Return None only if `username` is None.
+    """
+    def replace_e(match: re.Match) -> str:
+        char = "е" if match[2] == "e" else "Е"
+        return match[1] + char
+
+    if username:
+        return re.sub(r"(clyd)(e)", replace_e, username, flags=re.I)
+    else:
+        return username  # Empty string or None
diff --git a/bot/utils/redis_cache.py b/bot/utils/redis_cache.py
index de80cee84..58cfe1df5 100644
--- a/bot/utils/redis_cache.py
+++ b/bot/utils/redis_cache.py
@@ -11,7 +11,7 @@ log = logging.getLogger(__name__)
 
 # Type aliases
 RedisKeyType = Union[str, int]
-RedisValueType = Union[str, int, float]
+RedisValueType = Union[str, int, float, bool]
 RedisKeyOrValue = Union[RedisKeyType, RedisValueType]
 
 # Prefix tuples
@@ -20,6 +20,7 @@ _VALUE_PREFIXES = (
     ("f|", float),
     ("i|", int),
     ("s|", str),
+    ("b|", bool),
 )
 _KEY_PREFIXES = (
     ("i|", int),
@@ -47,8 +48,8 @@ class RedisCache:
     behaves, and should be familiar to Python users. The biggest difference is that
     all the public methods in this class are coroutines, and must be awaited.
 
-    Because of limitations in Redis, this cache will only accept strings, integers and
-    floats both for keys and values.
+    Because of limitations in Redis, this cache will only accept strings and integers for keys,
+    and strings, integers, floats and booleans for values.
 
     Please note that this class MUST be created as a class attribute, and that that class
     must also contain an attribute with an instance of our Bot. See `__get__` and `__set_name__`
@@ -100,16 +101,7 @@ class RedisCache:
 
     def _set_namespace(self, namespace: str) -> None:
         """Try to set the namespace, but do not permit collisions."""
-        # We need a unique namespace, to prevent collisions. This loop
-        # will try appending underscores to the end of the namespace until
-        # it finds one that is unique.
-        #
-        # For example, if `john` and `john_`  are both taken, the namespace will
-        # be `john__` at the end of this loop.
-        while namespace in self._namespaces:
-            namespace += "_"
-
-        log.trace(f"RedisCache setting namespace to {self._namespace}")
+        log.trace(f"RedisCache setting namespace to {namespace}")
         self._namespaces.append(namespace)
         self._namespace = namespace
 
@@ -117,8 +109,15 @@ class RedisCache:
     def _to_typestring(key_or_value: RedisKeyOrValue, prefixes: _PrefixTuple) -> str:
         """Turn a valid Redis type into a typestring."""
         for prefix, _type in prefixes:
-            if isinstance(key_or_value, _type):
+            # Convert bools into integers before storing them.
+            if type(key_or_value) is bool:
+                bool_int = int(key_or_value)
+                return f"{prefix}{bool_int}"
+
+            # isinstance is a bad idea here, because isintance(False, int) == True.
+            if type(key_or_value) is _type:
                 return f"{prefix}{key_or_value}"
+
         raise TypeError(f"RedisCache._to_typestring only supports the following: {prefixes}.")
 
     @staticmethod
@@ -131,6 +130,13 @@ class RedisCache:
         # Now we convert our unicode string back into the type it originally was.
         for prefix, _type in prefixes:
             if key_or_value.startswith(prefix):
+
+                # For booleans, we need special handling because bool("False") is True.
+                if prefix == "b|":
+                    value = key_or_value[len(prefix):]
+                    return bool(int(value))
+
+                # Otherwise we can just convert normally.
                 return _type(key_or_value[len(prefix):])
         raise TypeError(f"RedisCache._from_typestring only supports the following: {prefixes}.")
 
diff --git a/config-default.yml b/config-default.yml
index 2c85f5ef3..64c4e715b 100644
--- a/config-default.yml
+++ b/config-default.yml
@@ -142,6 +142,7 @@ guild:
 
         # Python Help: Available
         how_to_get_help:    704250143020417084
+        cooldown:           720603994149486673
 
         # Logs
         attachment_log:     &ATTACH_LOG     649243850006855680
@@ -268,7 +269,8 @@ filter:
     notify_user_domains:     false
 
     # Filter configuration
-    ping_everyone: true  # Ping @everyone when we send a mod-alert?
+    ping_everyone:             true  # Ping @everyone when we send a mod-alert?
+    offensive_msg_delete_days: 7     # How many days before deleting an offensive message?
 
     guild_invite_whitelist:
         - 280033776820813825  # Functional Programming
@@ -297,6 +299,8 @@ filter:
         - 613425648685547541  # Discord Developers
         - 185590609631903755  # Blender Hub
         - 420324994703163402  # /r/FlutterDev
+        - 488751051629920277  # Python Atlanta
+        - 143867839282020352  # C#
 
     domain_blacklist:
         - pornhub.com
@@ -328,6 +332,7 @@ filter:
         - ssteam.site
         - steamwalletgift.com
         - discord.gift
+        - lmgtfy.com
 
     word_watchlist:
         - goo+ks*
diff --git a/docker-compose.yml b/docker-compose.yml
index 9884e35f0..cff7d33d6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -17,6 +17,14 @@ services:
     ports:
       - "127.0.0.1:6379:6379"
 
+  snekbox:
+    image: pythondiscord/snekbox:latest
+    init: true
+    ipc: none
+    ports:
+     - "127.0.0.1:8060:8060"
+    privileged: true
+
   web:
     image: pythondiscord/site:latest
     command: ["run", "--debug"]
@@ -47,6 +55,7 @@ services:
     depends_on:
       - web
       - redis
+      - snekbox
     environment:
       BOT_TOKEN: ${BOT_TOKEN}
       BOT_API_KEY: badbot13m0n8f570f942013fc818f234916ca531
diff --git a/tests/bot/cogs/moderation/test_infractions.py b/tests/bot/cogs/moderation/test_infractions.py
new file mode 100644
index 000000000..da4e92ccc
--- /dev/null
+++ b/tests/bot/cogs/moderation/test_infractions.py
@@ -0,0 +1,55 @@
+import textwrap
+import unittest
+from unittest.mock import AsyncMock, Mock, patch
+
+from bot.cogs.moderation.infractions import Infractions
+from tests.helpers import MockBot, MockContext, MockGuild, MockMember, MockRole
+
+
+class TruncationTests(unittest.IsolatedAsyncioTestCase):
+    """Tests for ban and kick command reason truncation."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.cog = Infractions(self.bot)
+        self.user = MockMember(id=1234, top_role=MockRole(id=3577, position=10))
+        self.target = MockMember(id=1265, top_role=MockRole(id=9876, position=0))
+        self.guild = MockGuild(id=4567)
+        self.ctx = MockContext(bot=self.bot, author=self.user, guild=self.guild)
+
+    @patch("bot.cogs.moderation.utils.get_active_infraction")
+    @patch("bot.cogs.moderation.utils.post_infraction")
+    async def test_apply_ban_reason_truncation(self, post_infraction_mock, get_active_mock):
+        """Should truncate reason for `ctx.guild.ban`."""
+        get_active_mock.return_value = None
+        post_infraction_mock.return_value = {"foo": "bar"}
+
+        self.cog.apply_infraction = AsyncMock()
+        self.bot.get_cog.return_value = AsyncMock()
+        self.cog.mod_log.ignore = Mock()
+        self.ctx.guild.ban = Mock()
+
+        await self.cog.apply_ban(self.ctx, self.target, "foo bar" * 3000)
+        self.ctx.guild.ban.assert_called_once_with(
+            self.target,
+            reason=textwrap.shorten("foo bar" * 3000, 512, placeholder="..."),
+            delete_message_days=0
+        )
+        self.cog.apply_infraction.assert_awaited_once_with(
+            self.ctx, {"foo": "bar"}, self.target, self.ctx.guild.ban.return_value
+        )
+
+    @patch("bot.cogs.moderation.utils.post_infraction")
+    async def test_apply_kick_reason_truncation(self, post_infraction_mock):
+        """Should truncate reason for `Member.kick`."""
+        post_infraction_mock.return_value = {"foo": "bar"}
+
+        self.cog.apply_infraction = AsyncMock()
+        self.cog.mod_log.ignore = Mock()
+        self.target.kick = Mock()
+
+        await self.cog.apply_kick(self.ctx, self.target, "foo bar" * 3000)
+        self.target.kick.assert_called_once_with(reason=textwrap.shorten("foo bar" * 3000, 512, placeholder="..."))
+        self.cog.apply_infraction.assert_awaited_once_with(
+            self.ctx, {"foo": "bar"}, self.target, self.target.kick.return_value
+        )
diff --git a/tests/bot/cogs/moderation/test_modlog.py b/tests/bot/cogs/moderation/test_modlog.py
new file mode 100644
index 000000000..f2809f40a
--- /dev/null
+++ b/tests/bot/cogs/moderation/test_modlog.py
@@ -0,0 +1,29 @@
+import unittest
+
+import discord
+
+from bot.cogs.moderation.modlog import ModLog
+from tests.helpers import MockBot, MockTextChannel
+
+
+class ModLogTests(unittest.IsolatedAsyncioTestCase):
+    """Tests for moderation logs."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.cog = ModLog(self.bot)
+        self.channel = MockTextChannel()
+
+    async def test_log_entry_description_truncation(self):
+        """Test that embed description for ModLog entry is truncated."""
+        self.bot.get_channel.return_value = self.channel
+        await self.cog.send_log_message(
+            icon_url="foo",
+            colour=discord.Colour.blue(),
+            title="bar",
+            text="foo bar" * 3000
+        )
+        embed = self.channel.send.call_args[1]["embed"]
+        self.assertEqual(
+            embed.description, ("foo bar" * 3000)[:2045] + "..."
+        )
diff --git a/tests/bot/cogs/moderation/test_silence.py b/tests/bot/cogs/moderation/test_silence.py
index 3fd149f04..ab3d0742a 100644
--- a/tests/bot/cogs/moderation/test_silence.py
+++ b/tests/bot/cogs/moderation/test_silence.py
@@ -127,10 +127,20 @@ class SilenceTests(unittest.IsolatedAsyncioTestCase):
             self.ctx.reset_mock()
 
     async def test_unsilence_sent_correct_discord_message(self):
-        """Proper reply after a successful unsilence."""
-        with mock.patch.object(self.cog, "_unsilence", return_value=True):
-            await self.cog.unsilence.callback(self.cog, self.ctx)
-            self.ctx.send.assert_called_once_with(f"{Emojis.check_mark} unsilenced current channel.")
+        """Check if proper message was sent when unsilencing channel."""
+        test_cases = (
+            (True, f"{Emojis.check_mark} unsilenced current channel."),
+            (False, f"{Emojis.cross_mark} current channel was not silenced.")
+        )
+        for _unsilence_patch_return, result_message in test_cases:
+            with self.subTest(
+                starting_silenced_state=_unsilence_patch_return,
+                result_message=result_message
+            ):
+                with mock.patch.object(self.cog, "_unsilence", return_value=_unsilence_patch_return):
+                    await self.cog.unsilence.callback(self.cog, self.ctx)
+                    self.ctx.send.assert_called_once_with(result_message)
+            self.ctx.reset_mock()
 
     async def test_silence_private_for_false(self):
         """Permissions are not set and `False` is returned in an already silenced channel."""
diff --git a/tests/bot/cogs/sync/test_cog.py b/tests/bot/cogs/sync/test_cog.py
index 81398c61f..14fd909c4 100644
--- a/tests/bot/cogs/sync/test_cog.py
+++ b/tests/bot/cogs/sync/test_cog.py
@@ -247,14 +247,12 @@ class SyncCogListenerTests(SyncCogTestCase):
         before_data = {
             "name": "old name",
             "discriminator": "1234",
-            "avatar": "old avatar",
             "bot": False,
         }
 
         subtests = (
             (True, "name", "name", "new name", "new name"),
             (True, "discriminator", "discriminator", "8765", 8765),
-            (True, "avatar", "avatar_hash", "9j2e9", "9j2e9"),
             (False, "bot", "bot", True, True),
         )
 
@@ -295,7 +293,6 @@ class SyncCogListenerTests(SyncCogTestCase):
         )
 
         data = {
-            "avatar_hash": member.avatar,
             "discriminator": int(member.discriminator),
             "id": member.id,
             "in_guild": True,
diff --git a/tests/bot/cogs/sync/test_users.py b/tests/bot/cogs/sync/test_users.py
index 818883012..002a947ad 100644
--- a/tests/bot/cogs/sync/test_users.py
+++ b/tests/bot/cogs/sync/test_users.py
@@ -10,7 +10,6 @@ def fake_user(**kwargs):
     kwargs.setdefault("id", 43)
     kwargs.setdefault("name", "bob the test man")
     kwargs.setdefault("discriminator", 1337)
-    kwargs.setdefault("avatar_hash", None)
     kwargs.setdefault("roles", (666,))
     kwargs.setdefault("in_guild", True)
 
@@ -32,7 +31,6 @@ class UserSyncerDiffTests(unittest.IsolatedAsyncioTestCase):
 
         for member in members:
             member = member.copy()
-            member["avatar"] = member.pop("avatar_hash")
             del member["in_guild"]
 
             mock_member = helpers.MockMember(**member)
diff --git a/tests/bot/cogs/test_antimalware.py b/tests/bot/cogs/test_antimalware.py
new file mode 100644
index 000000000..f219fc1ba
--- /dev/null
+++ b/tests/bot/cogs/test_antimalware.py
@@ -0,0 +1,159 @@
+import unittest
+from unittest.mock import AsyncMock, Mock, patch
+
+from discord import NotFound
+
+from bot.cogs import antimalware
+from bot.constants import AntiMalware as AntiMalwareConfig, Channels, STAFF_ROLES
+from tests.helpers import MockAttachment, MockBot, MockMessage, MockRole
+
+MODULE = "bot.cogs.antimalware"
+
+
+@patch(f"{MODULE}.AntiMalwareConfig.whitelist", new=[".first", ".second", ".third"])
+class AntiMalwareCogTests(unittest.IsolatedAsyncioTestCase):
+    """Test the AntiMalware cog."""
+
+    def setUp(self):
+        """Sets up fresh objects for each test."""
+        self.bot = MockBot()
+        self.cog = antimalware.AntiMalware(self.bot)
+        self.message = MockMessage()
+
+    async def test_message_with_allowed_attachment(self):
+        """Messages with allowed extensions should not be deleted"""
+        attachment = MockAttachment(filename=f"python{AntiMalwareConfig.whitelist[0]}")
+        self.message.attachments = [attachment]
+
+        await self.cog.on_message(self.message)
+        self.message.delete.assert_not_called()
+
+    async def test_message_without_attachment(self):
+        """Messages without attachments should result in no action."""
+        await self.cog.on_message(self.message)
+        self.message.delete.assert_not_called()
+
+    async def test_direct_message_with_attachment(self):
+        """Direct messages should have no action taken."""
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+        self.message.guild = None
+
+        await self.cog.on_message(self.message)
+
+        self.message.delete.assert_not_called()
+
+    async def test_message_with_illegal_extension_gets_deleted(self):
+        """A message containing an illegal extension should send an embed."""
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+
+        await self.cog.on_message(self.message)
+
+        self.message.delete.assert_called_once()
+
+    async def test_message_send_by_staff(self):
+        """A message send by a member of staff should be ignored."""
+        staff_role = MockRole(id=STAFF_ROLES[0])
+        self.message.author.roles.append(staff_role)
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+
+        await self.cog.on_message(self.message)
+
+        self.message.delete.assert_not_called()
+
+    async def test_python_file_redirect_embed_description(self):
+        """A message containing a .py file should result in an embed redirecting the user to our paste site"""
+        attachment = MockAttachment(filename="python.py")
+        self.message.attachments = [attachment]
+        self.message.channel.send = AsyncMock()
+
+        await self.cog.on_message(self.message)
+        self.message.channel.send.assert_called_once()
+        args, kwargs = self.message.channel.send.call_args
+        embed = kwargs.pop("embed")
+
+        self.assertEqual(embed.description, antimalware.PY_EMBED_DESCRIPTION)
+
+    async def test_txt_file_redirect_embed_description(self):
+        """A message containing a .txt file should result in the correct embed."""
+        attachment = MockAttachment(filename="python.txt")
+        self.message.attachments = [attachment]
+        self.message.channel.send = AsyncMock()
+        antimalware.TXT_EMBED_DESCRIPTION = Mock()
+        antimalware.TXT_EMBED_DESCRIPTION.format.return_value = "test"
+
+        await self.cog.on_message(self.message)
+        self.message.channel.send.assert_called_once()
+        args, kwargs = self.message.channel.send.call_args
+        embed = kwargs.pop("embed")
+        cmd_channel = self.bot.get_channel(Channels.bot_commands)
+
+        self.assertEqual(embed.description, antimalware.TXT_EMBED_DESCRIPTION.format.return_value)
+        antimalware.TXT_EMBED_DESCRIPTION.format.assert_called_with(cmd_channel_mention=cmd_channel.mention)
+
+    async def test_other_disallowed_extention_embed_description(self):
+        """Test the description for a non .py/.txt disallowed extension."""
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+        self.message.channel.send = AsyncMock()
+        antimalware.DISALLOWED_EMBED_DESCRIPTION = Mock()
+        antimalware.DISALLOWED_EMBED_DESCRIPTION.format.return_value = "test"
+
+        await self.cog.on_message(self.message)
+        self.message.channel.send.assert_called_once()
+        args, kwargs = self.message.channel.send.call_args
+        embed = kwargs.pop("embed")
+        meta_channel = self.bot.get_channel(Channels.meta)
+
+        self.assertEqual(embed.description, antimalware.DISALLOWED_EMBED_DESCRIPTION.format.return_value)
+        antimalware.DISALLOWED_EMBED_DESCRIPTION.format.assert_called_with(
+            blocked_extensions_str=".disallowed",
+            meta_channel_mention=meta_channel.mention
+        )
+
+    async def test_removing_deleted_message_logs(self):
+        """Removing an already deleted message logs the correct message"""
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+        self.message.delete = AsyncMock(side_effect=NotFound(response=Mock(status=""), message=""))
+
+        with self.assertLogs(logger=antimalware.log, level="INFO"):
+            await self.cog.on_message(self.message)
+        self.message.delete.assert_called_once()
+
+    async def test_message_with_illegal_attachment_logs(self):
+        """Deleting a message with an illegal attachment should result in a log."""
+        attachment = MockAttachment(filename="python.disallowed")
+        self.message.attachments = [attachment]
+
+        with self.assertLogs(logger=antimalware.log, level="INFO"):
+            await self.cog.on_message(self.message)
+
+    async def test_get_disallowed_extensions(self):
+        """The return value should include all non-whitelisted extensions."""
+        test_values = (
+            ([], []),
+            (AntiMalwareConfig.whitelist, []),
+            ([".first"], []),
+            ([".first", ".disallowed"], [".disallowed"]),
+            ([".disallowed"], [".disallowed"]),
+            ([".disallowed", ".illegal"], [".disallowed", ".illegal"]),
+        )
+
+        for extensions, expected_disallowed_extensions in test_values:
+            with self.subTest(extensions=extensions, expected_disallowed_extensions=expected_disallowed_extensions):
+                self.message.attachments = [MockAttachment(filename=f"filename{extension}") for extension in extensions]
+                disallowed_extensions = self.cog.get_disallowed_extensions(self.message)
+                self.assertCountEqual(disallowed_extensions, expected_disallowed_extensions)
+
+
+class AntiMalwareSetupTests(unittest.TestCase):
+    """Tests setup of the `AntiMalware` cog."""
+
+    def test_setup(self):
+        """Setup of the extension should call add_cog."""
+        bot = MockBot()
+        antimalware.setup(bot)
+        bot.add_cog.assert_called_once()
diff --git a/tests/bot/cogs/test_information.py b/tests/bot/cogs/test_information.py
index aca6b594f..79c0e0ad3 100644
--- a/tests/bot/cogs/test_information.py
+++ b/tests/bot/cogs/test_information.py
@@ -148,14 +148,18 @@ class InformationCogTests(unittest.TestCase):
                 Voice region: {self.ctx.guild.region}
                 Features: {', '.join(self.ctx.guild.features)}
 
-                **Counts**
-                Members: {self.ctx.guild.member_count:,}
-                Roles: {len(self.ctx.guild.roles)}
+                **Channel counts**
                 Category channels: 1
                 Text channels: 1
                 Voice channels: 1
+                Staff channels: 0
+
+                **Member counts**
+                Members: {self.ctx.guild.member_count:,}
+                Staff members: 0
+                Roles: {len(self.ctx.guild.roles)}
 
-                **Members**
+                **Member statuses**
                 {constants.Emojis.status_online} 2
                 {constants.Emojis.status_idle} 1
                 {constants.Emojis.status_dnd} 4
diff --git a/tests/bot/cogs/test_token_remover.py b/tests/bot/cogs/test_token_remover.py
index 33d1ec170..3349caa73 100644
--- a/tests/bot/cogs/test_token_remover.py
+++ b/tests/bot/cogs/test_token_remover.py
@@ -1,56 +1,89 @@
-import asyncio
-import logging
 import unittest
-from unittest.mock import AsyncMock, MagicMock
+from re import Match
+from unittest import mock
+from unittest.mock import MagicMock
 
-from discord import Colour
+from discord import Colour, NotFound
 
-from bot.cogs.token_remover import (
-    DELETION_MESSAGE_TEMPLATE,
-    TokenRemover,
-    setup as setup_cog,
-)
-from bot.constants import Channels, Colours, Event, Icons
-from tests.helpers import MockBot, MockMessage
+from bot import constants
+from bot.cogs import token_remover
+from bot.cogs.moderation import ModLog
+from bot.cogs.token_remover import Token, TokenRemover
+from tests.helpers import MockBot, MockMessage, autospec
 
 
-class TokenRemoverTests(unittest.TestCase):
+class TokenRemoverTests(unittest.IsolatedAsyncioTestCase):
     """Tests the `TokenRemover` cog."""
 
     def setUp(self):
         """Adds the cog, a bot, and a message to the instance for usage in tests."""
         self.bot = MockBot()
-        self.bot.get_cog.return_value = MagicMock()
-        self.bot.get_cog.return_value.send_log_message = AsyncMock()
         self.cog = TokenRemover(bot=self.bot)
 
-        self.msg = MockMessage(id=555, content='')
-        self.msg.author.__str__ = MagicMock()
-        self.msg.author.__str__.return_value = 'lemon'
-        self.msg.author.bot = False
-        self.msg.author.avatar_url_as.return_value = 'picture-lemon.png'
-        self.msg.author.id = 42
-        self.msg.author.mention = '@lemon'
+        self.msg = MockMessage(id=555, content="hello world")
         self.msg.channel.mention = "#lemonade-stand"
+        self.msg.author.__str__ = MagicMock(return_value=self.msg.author.name)
+        self.msg.author.avatar_url_as.return_value = "picture-lemon.png"
 
-    def test_is_valid_user_id_is_true_for_numeric_content(self):
-        """A string decoding to numeric characters is a valid user ID."""
-        # MTIz = base64(123)
-        self.assertTrue(TokenRemover.is_valid_user_id('MTIz'))
+    def test_is_valid_user_id_valid(self):
+        """Should consider user IDs valid if they decode entirely to ASCII digits."""
+        ids = (
+            "NDcyMjY1OTQzMDYyNDEzMzMy",
+            "NDc1MDczNjI5Mzk5NTQ3OTA0",
+            "NDY3MjIzMjMwNjUwNzc3NjQx",
+        )
+
+        for user_id in ids:
+            with self.subTest(user_id=user_id):
+                result = TokenRemover.is_valid_user_id(user_id)
+                self.assertTrue(result)
 
-    def test_is_valid_user_id_is_false_for_alphabetic_content(self):
-        """A string decoding to alphabetic characters is not a valid user ID."""
-        # YWJj = base64(abc)
-        self.assertFalse(TokenRemover.is_valid_user_id('YWJj'))
+    def test_is_valid_user_id_invalid(self):
+        """Should consider non-digit and non-ASCII IDs invalid."""
+        ids = (
+            ("SGVsbG8gd29ybGQ", "non-digit ASCII"),
+            ("0J_RgNC40LLQtdGCINC80LjRgA", "cyrillic text"),
+            ("4pO14p6L4p6C4pG34p264pGl8J-EiOKSj-KCieKBsA", "Unicode digits"),
+            ("4oaA4oaB4oWh4oWi4Lyz4Lyq4Lyr4LG9", "Unicode numerals"),
+            ("8J2fjvCdn5nwnZ-k8J2fr_Cdn7rgravvvJngr6c", "Unicode decimals"),
+            ("{hello}[world]&(bye!)", "ASCII invalid Base64"),
+            ("Þíß-ï§-ňøẗ-våłìÐ", "Unicode invalid Base64"),
+        )
 
-    def test_is_valid_timestamp_is_true_for_valid_timestamps(self):
-        """A string decoding to a valid timestamp should be recognized as such."""
-        self.assertTrue(TokenRemover.is_valid_timestamp('DN9r_A'))
+        for user_id, msg in ids:
+            with self.subTest(msg=msg):
+                result = TokenRemover.is_valid_user_id(user_id)
+                self.assertFalse(result)
 
-    def test_is_valid_timestamp_is_false_for_invalid_values(self):
-        """A string not decoding to a valid timestamp should not be recognized as such."""
-        # MTIz = base64(123)
-        self.assertFalse(TokenRemover.is_valid_timestamp('MTIz'))
+    def test_is_valid_timestamp_valid(self):
+        """Should consider timestamps valid if they're greater than the Discord epoch."""
+        timestamps = (
+            "XsyRkw",
+            "Xrim9Q",
+            "XsyR-w",
+            "XsySD_",
+            "Dn9r_A",
+        )
+
+        for timestamp in timestamps:
+            with self.subTest(timestamp=timestamp):
+                result = TokenRemover.is_valid_timestamp(timestamp)
+                self.assertTrue(result)
+
+    def test_is_valid_timestamp_invalid(self):
+        """Should consider timestamps invalid if they're before Discord epoch or can't be parsed."""
+        timestamps = (
+            ("B4Yffw", "DISCORD_EPOCH - TOKEN_EPOCH - 1"),
+            ("ew", "123"),
+            ("AoIKgA", "42076800"),
+            ("{hello}[world]&(bye!)", "ASCII invalid Base64"),
+            ("Þíß-ï§-ňøẗ-våłìÐ", "Unicode invalid Base64"),
+        )
+
+        for timestamp, msg in timestamps:
+            with self.subTest(msg=msg):
+                result = TokenRemover.is_valid_timestamp(timestamp)
+                self.assertFalse(result)
 
     def test_mod_log_property(self):
         """The `mod_log` property should ask the bot to return the `ModLog` cog."""
@@ -58,74 +91,220 @@ class TokenRemoverTests(unittest.TestCase):
         self.assertEqual(self.cog.mod_log, self.bot.get_cog.return_value)
         self.bot.get_cog.assert_called_once_with('ModLog')
 
-    def test_ignores_bot_messages(self):
-        """When the message event handler is called with a bot message, nothing is done."""
-        self.msg.author.bot = True
-        coroutine = self.cog.on_message(self.msg)
-        self.assertIsNone(asyncio.run(coroutine))
-
-    def test_ignores_messages_without_tokens(self):
-        """Messages without anything looking like a token are ignored."""
-        for content in ('', 'lemon wins'):
-            with self.subTest(content=content):
-                self.msg.content = content
-                coroutine = self.cog.on_message(self.msg)
-                self.assertIsNone(asyncio.run(coroutine))
-
-    def test_ignores_messages_with_invalid_tokens(self):
-        """Messages with values that are invalid tokens are ignored."""
-        for content in ('foo.bar.baz', 'x.y.'):
-            with self.subTest(content=content):
-                self.msg.content = content
-                coroutine = self.cog.on_message(self.msg)
-                self.assertIsNone(asyncio.run(coroutine))
-
-    def test_censors_valid_tokens(self):
-        """Valid tokens are censored."""
-        cases = (
-            # (content, censored_token)
-            ('MTIz.DN9R_A.xyz', 'MTIz.DN9R_A.xxx'),
+    async def test_on_message_edit_uses_on_message(self):
+        """The edit listener should delegate handling of the message to the normal listener."""
+        self.cog.on_message = mock.create_autospec(self.cog.on_message, spec_set=True)
+
+        await self.cog.on_message_edit(MockMessage(), self.msg)
+        self.cog.on_message.assert_awaited_once_with(self.msg)
+
+    @autospec(TokenRemover, "find_token_in_message", "take_action")
+    async def test_on_message_takes_action(self, find_token_in_message, take_action):
+        """Should take action if a valid token is found when a message is sent."""
+        cog = TokenRemover(self.bot)
+        found_token = "foobar"
+        find_token_in_message.return_value = found_token
+
+        await cog.on_message(self.msg)
+
+        find_token_in_message.assert_called_once_with(self.msg)
+        take_action.assert_awaited_once_with(cog, self.msg, found_token)
+
+    @autospec(TokenRemover, "find_token_in_message", "take_action")
+    async def test_on_message_skips_missing_token(self, find_token_in_message, take_action):
+        """Shouldn't take action if a valid token isn't found when a message is sent."""
+        cog = TokenRemover(self.bot)
+        find_token_in_message.return_value = False
+
+        await cog.on_message(self.msg)
+
+        find_token_in_message.assert_called_once_with(self.msg)
+        take_action.assert_not_awaited()
+
+    @autospec(TokenRemover, "find_token_in_message")
+    async def test_on_message_ignores_dms_bots(self, find_token_in_message):
+        """Shouldn't parse a message if it is a DM or authored by a bot."""
+        cog = TokenRemover(self.bot)
+        dm_msg = MockMessage(guild=None)
+        bot_msg = MockMessage(author=MagicMock(bot=True))
+
+        for msg in (dm_msg, bot_msg):
+            await cog.on_message(msg)
+            find_token_in_message.assert_not_called()
+
+    @autospec("bot.cogs.token_remover", "TOKEN_RE")
+    def test_find_token_no_matches(self, token_re):
+        """None should be returned if the regex matches no tokens in a message."""
+        token_re.finditer.return_value = ()
+
+        return_value = TokenRemover.find_token_in_message(self.msg)
+
+        self.assertIsNone(return_value)
+        token_re.finditer.assert_called_once_with(self.msg.content)
+
+    @autospec(TokenRemover, "is_valid_user_id", "is_valid_timestamp")
+    @autospec("bot.cogs.token_remover", "Token")
+    @autospec("bot.cogs.token_remover", "TOKEN_RE")
+    def test_find_token_valid_match(self, token_re, token_cls, is_valid_id, is_valid_timestamp):
+        """The first match with a valid user ID and timestamp should be returned as a `Token`."""
+        matches = [
+            mock.create_autospec(Match, spec_set=True, instance=True),
+            mock.create_autospec(Match, spec_set=True, instance=True),
+        ]
+        tokens = [
+            mock.create_autospec(Token, spec_set=True, instance=True),
+            mock.create_autospec(Token, spec_set=True, instance=True),
+        ]
+
+        token_re.finditer.return_value = matches
+        token_cls.side_effect = tokens
+        is_valid_id.side_effect = (False, True)  # The 1st match will be invalid, 2nd one valid.
+        is_valid_timestamp.return_value = True
+
+        return_value = TokenRemover.find_token_in_message(self.msg)
+
+        self.assertEqual(tokens[1], return_value)
+        token_re.finditer.assert_called_once_with(self.msg.content)
+
+    @autospec(TokenRemover, "is_valid_user_id", "is_valid_timestamp")
+    @autospec("bot.cogs.token_remover", "Token")
+    @autospec("bot.cogs.token_remover", "TOKEN_RE")
+    def test_find_token_invalid_matches(self, token_re, token_cls, is_valid_id, is_valid_timestamp):
+        """None should be returned if no matches have valid user IDs or timestamps."""
+        token_re.finditer.return_value = [mock.create_autospec(Match, spec_set=True, instance=True)]
+        token_cls.return_value = mock.create_autospec(Token, spec_set=True, instance=True)
+        is_valid_id.return_value = False
+        is_valid_timestamp.return_value = False
+
+        return_value = TokenRemover.find_token_in_message(self.msg)
+
+        self.assertIsNone(return_value)
+        token_re.finditer.assert_called_once_with(self.msg.content)
+
+    def test_regex_invalid_tokens(self):
+        """Messages without anything looking like a token are not matched."""
+        tokens = (
+            "",
+            "lemon wins",
+            "..",
+            "x.y",
+            "x.y.",
+            ".y.z",
+            ".y.",
+            "..z",
+            "x..z",
+            " . . ",
+            "\n.\n.\n",
+            "hellö.world.bye",
+            "base64.nötbåse64.morebase64",
+            "19jd3J.dfkm3d.€víł§tüff",
+        )
+
+        for token in tokens:
+            with self.subTest(token=token):
+                results = token_remover.TOKEN_RE.findall(token)
+                self.assertEqual(len(results), 0)
+
+    def test_regex_valid_tokens(self):
+        """Messages that look like tokens should be matched."""
+        # Don't worry, these tokens have been invalidated.
+        tokens = (
+            "NDcyMjY1OTQzMDYy_DEzMz-y.XsyRkw.VXmErH7j511turNpfURmb0rVNm8",
+            "NDcyMjY1OTQzMDYyNDEzMzMy.Xrim9Q.Ysnu2wacjaKs7qnoo46S8Dm2us8",
+            "NDc1MDczNjI5Mzk5NTQ3OTA0.XsyR-w.sJf6omBPORBPju3WJEIAcwW9Zds",
+            "NDY3MjIzMjMwNjUwNzc3NjQx.XsySD_.s45jqDV_Iisn-symw0yDRrk_jf4",
+        )
+
+        for token in tokens:
+            with self.subTest(token=token):
+                results = token_remover.TOKEN_RE.fullmatch(token)
+                self.assertIsNotNone(results, f"{token} was not matched by the regex")
+
+    def test_regex_matches_multiple_valid(self):
+        """Should support multiple matches in the middle of a string."""
+        token_1 = "NDY3MjIzMjMwNjUwNzc3NjQx.XsyWGg.uFNEQPCc4ePwGh7egG8UicQssz8"
+        token_2 = "NDcyMjY1OTQzMDYyNDEzMzMy.XsyWMw.l8XPnDqb0lp-EiQ2g_0xVFT1pyc"
+        message = f"garbage {token_1} hello {token_2} world"
+
+        results = token_remover.TOKEN_RE.finditer(message)
+        results = [match[0] for match in results]
+        self.assertCountEqual((token_1, token_2), results)
+
+    @autospec("bot.cogs.token_remover", "LOG_MESSAGE")
+    def test_format_log_message(self, log_message):
+        """Should correctly format the log message with info from the message and token."""
+        token = Token("NDY3MjIzMjMwNjUwNzc3NjQx", "XsySD_", "s45jqDV_Iisn-symw0yDRrk_jf4")
+        log_message.format.return_value = "Howdy"
+
+        return_value = TokenRemover.format_log_message(self.msg, token)
+
+        self.assertEqual(return_value, log_message.format.return_value)
+        log_message.format.assert_called_once_with(
+            author=self.msg.author,
+            author_id=self.msg.author.id,
+            channel=self.msg.channel.mention,
+            user_id=token.user_id,
+            timestamp=token.timestamp,
+            hmac="x" * len(token.hmac),
+        )
+
+    @mock.patch.object(TokenRemover, "mod_log", new_callable=mock.PropertyMock)
+    @autospec("bot.cogs.token_remover", "log")
+    @autospec(TokenRemover, "format_log_message")
+    async def test_take_action(self, format_log_message, logger, mod_log_property):
+        """Should delete the message and send a mod log."""
+        cog = TokenRemover(self.bot)
+        mod_log = mock.create_autospec(ModLog, spec_set=True, instance=True)
+        token = mock.create_autospec(Token, spec_set=True, instance=True)
+        log_msg = "testing123"
+
+        mod_log_property.return_value = mod_log
+        format_log_message.return_value = log_msg
+
+        await cog.take_action(self.msg, token)
+
+        self.msg.delete.assert_called_once_with()
+        self.msg.channel.send.assert_called_once_with(
+            token_remover.DELETION_MESSAGE_TEMPLATE.format(mention=self.msg.author.mention)
+        )
+
+        format_log_message.assert_called_once_with(self.msg, token)
+        logger.debug.assert_called_with(log_msg)
+        self.bot.stats.incr.assert_called_once_with("tokens.removed_tokens")
+
+        mod_log.ignore.assert_called_once_with(constants.Event.message_delete, self.msg.id)
+        mod_log.send_log_message.assert_called_once_with(
+            icon_url=constants.Icons.token_removed,
+            colour=Colour(constants.Colours.soft_red),
+            title="Token removed!",
+            text=log_msg,
+            thumbnail=self.msg.author.avatar_url_as.return_value,
+            channel_id=constants.Channels.mod_alerts
         )
 
-        for content, censored_token in cases:
-            with self.subTest(content=content, censored_token=censored_token):
-                self.msg.content = content
-                coroutine = self.cog.on_message(self.msg)
-                with self.assertLogs(logger='bot.cogs.token_remover', level=logging.DEBUG) as cm:
-                    self.assertIsNone(asyncio.run(coroutine))  # no return value
-
-                [line] = cm.output
-                log_message = (
-                    "Censored a seemingly valid token sent by "
-                    "lemon (`42`) in #lemonade-stand, "
-                    f"token was `{censored_token}`"
-                )
-                self.assertIn(log_message, line)
-
-                self.msg.delete.assert_called_once_with()
-                self.msg.channel.send.assert_called_once_with(
-                    DELETION_MESSAGE_TEMPLATE.format(mention='@lemon')
-                )
-                self.bot.get_cog.assert_called_with('ModLog')
-                self.msg.author.avatar_url_as.assert_called_once_with(static_format='png')
-
-                mod_log = self.bot.get_cog.return_value
-                mod_log.ignore.assert_called_once_with(Event.message_delete, self.msg.id)
-                mod_log.send_log_message.assert_called_once_with(
-                    icon_url=Icons.token_removed,
-                    colour=Colour(Colours.soft_red),
-                    title="Token removed!",
-                    text=log_message,
-                    thumbnail='picture-lemon.png',
-                    channel_id=Channels.mod_alerts
-                )
-
-
-class TokenRemoverSetupTests(unittest.TestCase):
-    """Tests setup of the `TokenRemover` cog."""
-
-    def test_setup(self):
-        """Setup of the extension should call add_cog."""
+    @mock.patch.object(TokenRemover, "mod_log", new_callable=mock.PropertyMock)
+    async def test_take_action_delete_failure(self, mod_log_property):
+        """Shouldn't send any messages if the token message can't be deleted."""
+        cog = TokenRemover(self.bot)
+        mod_log_property.return_value = mock.create_autospec(ModLog, spec_set=True, instance=True)
+        self.msg.delete.side_effect = NotFound(MagicMock(), MagicMock())
+
+        token = mock.create_autospec(Token, spec_set=True, instance=True)
+        await cog.take_action(self.msg, token)
+
+        self.msg.delete.assert_called_once_with()
+        self.msg.channel.send.assert_not_awaited()
+
+
+class TokenRemoverExtensionTests(unittest.TestCase):
+    """Tests for the token_remover extension."""
+
+    @autospec("bot.cogs.token_remover", "TokenRemover")
+    def test_extension_setup(self, cog):
+        """The TokenRemover cog should be added."""
         bot = MockBot()
-        setup_cog(bot)
+        token_remover.setup(bot)
+
+        cog.assert_called_once_with(bot)
         bot.add_cog.assert_called_once()
+        self.assertTrue(isinstance(bot.add_cog.call_args.args[0], TokenRemover))
diff --git a/tests/bot/test_converters.py b/tests/bot/test_converters.py
index ca8cb6825..c42111f3f 100644
--- a/tests/bot/test_converters.py
+++ b/tests/bot/test_converters.py
@@ -1,5 +1,5 @@
-import asyncio
 import datetime
+import re
 import unittest
 from unittest.mock import MagicMock, patch
 
@@ -16,7 +16,7 @@ from bot.converters import (
 )
 
 
-class ConverterTests(unittest.TestCase):
+class ConverterTests(unittest.IsolatedAsyncioTestCase):
     """Tests our custom argument converters."""
 
     @classmethod
@@ -26,7 +26,7 @@ class ConverterTests(unittest.TestCase):
 
         cls.fixed_utc_now = datetime.datetime.fromisoformat('2019-01-01T00:00:00')
 
-    def test_tag_content_converter_for_valid(self):
+    async def test_tag_content_converter_for_valid(self):
         """TagContentConverter should return correct values for valid input."""
         test_values = (
             ('hello', 'hello'),
@@ -35,10 +35,10 @@ class ConverterTests(unittest.TestCase):
 
         for content, expected_conversion in test_values:
             with self.subTest(content=content, expected_conversion=expected_conversion):
-                conversion = asyncio.run(TagContentConverter.convert(self.context, content))
+                conversion = await TagContentConverter.convert(self.context, content)
                 self.assertEqual(conversion, expected_conversion)
 
-    def test_tag_content_converter_for_invalid(self):
+    async def test_tag_content_converter_for_invalid(self):
         """TagContentConverter should raise the proper exception for invalid input."""
         test_values = (
             ('', "Tag contents should not be empty, or filled with whitespace."),
@@ -47,10 +47,10 @@ class ConverterTests(unittest.TestCase):
 
         for value, exception_message in test_values:
             with self.subTest(tag_content=value, exception_message=exception_message):
-                with self.assertRaises(BadArgument, msg=exception_message):
-                    asyncio.run(TagContentConverter.convert(self.context, value))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await TagContentConverter.convert(self.context, value)
 
-    def test_tag_name_converter_for_valid(self):
+    async def test_tag_name_converter_for_valid(self):
         """TagNameConverter should return the correct values for valid tag names."""
         test_values = (
             ('tracebacks', 'tracebacks'),
@@ -60,10 +60,10 @@ class ConverterTests(unittest.TestCase):
 
         for name, expected_conversion in test_values:
             with self.subTest(name=name, expected_conversion=expected_conversion):
-                conversion = asyncio.run(TagNameConverter.convert(self.context, name))
+                conversion = await TagNameConverter.convert(self.context, name)
                 self.assertEqual(conversion, expected_conversion)
 
-    def test_tag_name_converter_for_invalid(self):
+    async def test_tag_name_converter_for_invalid(self):
         """TagNameConverter should raise the correct exception for invalid tag names."""
         test_values = (
             ('👋', "Don't be ridiculous, you can't use that character!"),
@@ -75,29 +75,29 @@ class ConverterTests(unittest.TestCase):
 
         for invalid_name, exception_message in test_values:
             with self.subTest(invalid_name=invalid_name, exception_message=exception_message):
-                with self.assertRaises(BadArgument, msg=exception_message):
-                    asyncio.run(TagNameConverter.convert(self.context, invalid_name))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await TagNameConverter.convert(self.context, invalid_name)
 
-    def test_valid_python_identifier_for_valid(self):
+    async def test_valid_python_identifier_for_valid(self):
         """ValidPythonIdentifier returns valid identifiers unchanged."""
         test_values = ('foo', 'lemon')
 
         for name in test_values:
             with self.subTest(identifier=name):
-                conversion = asyncio.run(ValidPythonIdentifier.convert(self.context, name))
+                conversion = await ValidPythonIdentifier.convert(self.context, name)
                 self.assertEqual(name, conversion)
 
-    def test_valid_python_identifier_for_invalid(self):
+    async def test_valid_python_identifier_for_invalid(self):
         """ValidPythonIdentifier raises the proper exception for invalid identifiers."""
         test_values = ('nested.stuff', '#####')
 
         for name in test_values:
             with self.subTest(identifier=name):
                 exception_message = f'`{name}` is not a valid Python identifier'
-                with self.assertRaises(BadArgument, msg=exception_message):
-                    asyncio.run(ValidPythonIdentifier.convert(self.context, name))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await ValidPythonIdentifier.convert(self.context, name)
 
-    def test_duration_converter_for_valid(self):
+    async def test_duration_converter_for_valid(self):
         """Duration returns the correct `datetime` for valid duration strings."""
         test_values = (
             # Simple duration strings
@@ -159,35 +159,35 @@ class ConverterTests(unittest.TestCase):
                 mock_datetime.utcnow.return_value = self.fixed_utc_now
 
                 with self.subTest(duration=duration, duration_dict=duration_dict):
-                    converted_datetime = asyncio.run(converter.convert(self.context, duration))
+                    converted_datetime = await converter.convert(self.context, duration)
                     self.assertEqual(converted_datetime, expected_datetime)
 
-    def test_duration_converter_for_invalid(self):
+    async def test_duration_converter_for_invalid(self):
         """Duration raises the right exception for invalid duration strings."""
         test_values = (
             # Units in wrong order
-            ('1d1w'),
-            ('1s1y'),
+            '1d1w',
+            '1s1y',
 
             # Duplicated units
-            ('1 year 2 years'),
-            ('1 M 10 minutes'),
+            '1 year 2 years',
+            '1 M 10 minutes',
 
             # Unknown substrings
-            ('1MVes'),
-            ('1y3breads'),
+            '1MVes',
+            '1y3breads',
 
             # Missing amount
-            ('ym'),
+            'ym',
 
             # Incorrect whitespace
-            (" 1y"),
-            ("1S "),
-            ("1y  1m"),
+            " 1y",
+            "1S ",
+            "1y  1m",
 
             # Garbage
-            ('Guido van Rossum'),
-            ('lemon lemon lemon lemon lemon lemon lemon'),
+            'Guido van Rossum',
+            'lemon lemon lemon lemon lemon lemon lemon',
         )
 
         converter = Duration()
@@ -195,10 +195,21 @@ class ConverterTests(unittest.TestCase):
         for invalid_duration in test_values:
             with self.subTest(invalid_duration=invalid_duration):
                 exception_message = f'`{invalid_duration}` is not a valid duration string.'
-                with self.assertRaises(BadArgument, msg=exception_message):
-                    asyncio.run(converter.convert(self.context, invalid_duration))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await converter.convert(self.context, invalid_duration)
 
-    def test_isodatetime_converter_for_valid(self):
+    @patch("bot.converters.datetime")
+    async def test_duration_converter_out_of_range(self, mock_datetime):
+        """Duration converter should raise BadArgument if datetime raises a ValueError."""
+        mock_datetime.__add__.side_effect = ValueError
+        mock_datetime.utcnow.return_value = mock_datetime
+
+        duration = f"{datetime.MAXYEAR}y"
+        exception_message = f"`{duration}` results in a datetime outside the supported range."
+        with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+            await Duration().convert(self.context, duration)
+
+    async def test_isodatetime_converter_for_valid(self):
         """ISODateTime converter returns correct datetime for valid datetime string."""
         test_values = (
             # `YYYY-mm-ddTHH:MM:SSZ` | `YYYY-mm-dd HH:MM:SSZ`
@@ -243,37 +254,37 @@ class ConverterTests(unittest.TestCase):
 
         for datetime_string, expected_dt in test_values:
             with self.subTest(datetime_string=datetime_string, expected_dt=expected_dt):
-                converted_dt = asyncio.run(converter.convert(self.context, datetime_string))
+                converted_dt = await converter.convert(self.context, datetime_string)
                 self.assertIsNone(converted_dt.tzinfo)
                 self.assertEqual(converted_dt, expected_dt)
 
-    def test_isodatetime_converter_for_invalid(self):
+    async def test_isodatetime_converter_for_invalid(self):
         """ISODateTime converter raises the correct exception for invalid datetime strings."""
         test_values = (
             # Make sure it doesn't interfere with the Duration converter
-            ('1Y'),
-            ('1d'),
-            ('1H'),
+            '1Y',
+            '1d',
+            '1H',
 
             # Check if it fails when only providing the optional time part
-            ('10:10:10'),
-            ('10:00'),
+            '10:10:10',
+            '10:00',
 
             # Invalid date format
-            ('19-01-01'),
+            '19-01-01',
 
             # Other non-valid strings
-            ('fisk the tag master'),
+            'fisk the tag master',
         )
 
         converter = ISODateTime()
         for datetime_string in test_values:
             with self.subTest(datetime_string=datetime_string):
                 exception_message = f"`{datetime_string}` is not a valid ISO-8601 datetime string"
-                with self.assertRaises(BadArgument, msg=exception_message):
-                    asyncio.run(converter.convert(self.context, datetime_string))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await converter.convert(self.context, datetime_string)
 
-    def test_hush_duration_converter_for_valid(self):
+    async def test_hush_duration_converter_for_valid(self):
         """HushDurationConverter returns correct value for minutes duration or `"forever"` strings."""
         test_values = (
             ("0", 0),
@@ -286,10 +297,10 @@ class ConverterTests(unittest.TestCase):
         converter = HushDurationConverter()
         for minutes_string, expected_minutes in test_values:
             with self.subTest(minutes_string=minutes_string, expected_minutes=expected_minutes):
-                converted = asyncio.run(converter.convert(self.context, minutes_string))
+                converted = await converter.convert(self.context, minutes_string)
                 self.assertEqual(expected_minutes, converted)
 
-    def test_hush_duration_converter_for_invalid(self):
+    async def test_hush_duration_converter_for_invalid(self):
         """HushDurationConverter raises correct exception for invalid minutes duration strings."""
         test_values = (
             ("16", "Duration must be at most 15 minutes."),
@@ -299,5 +310,5 @@ class ConverterTests(unittest.TestCase):
         converter = HushDurationConverter()
         for invalid_minutes_string, exception_message in test_values:
             with self.subTest(invalid_minutes_string=invalid_minutes_string, exception_message=exception_message):
-                with self.assertRaisesRegex(BadArgument, exception_message):
-                    asyncio.run(converter.convert(self.context, invalid_minutes_string))
+                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
+                    await converter.convert(self.context, invalid_minutes_string)
diff --git a/tests/bot/utils/test_messages.py b/tests/bot/utils/test_messages.py
new file mode 100644
index 000000000..9c22c9751
--- /dev/null
+++ b/tests/bot/utils/test_messages.py
@@ -0,0 +1,27 @@
+import unittest
+
+from bot.utils import messages
+
+
+class TestMessages(unittest.TestCase):
+    """Tests for functions in the `bot.utils.messages` module."""
+
+    def test_sub_clyde(self):
+        """Uppercase E's and lowercase e's are substituted with their cyrillic counterparts."""
+        sub_e = "\u0435"
+        sub_E = "\u0415"  # noqa: N806: Uppercase E in variable name
+
+        test_cases = (
+            (None, None),
+            ("", ""),
+            ("clyde", f"clyd{sub_e}"),
+            ("CLYDE", f"CLYD{sub_E}"),
+            ("cLyDe", f"cLyD{sub_e}"),
+            ("BIGclyde", f"BIGclyd{sub_e}"),
+            ("small clydeus the unholy", f"small clyd{sub_e}us the unholy"),
+            ("BIGCLYDE, babyclyde", f"BIGCLYD{sub_E}, babyclyd{sub_e}"),
+        )
+
+        for username_in, username_out in test_cases:
+            with self.subTest(input=username_in, expected_output=username_out):
+                self.assertEqual(messages.sub_clyde(username_in), username_out)
diff --git a/tests/bot/utils/test_redis_cache.py b/tests/bot/utils/test_redis_cache.py
index 8c1a40640..a2f0fe55d 100644
--- a/tests/bot/utils/test_redis_cache.py
+++ b/tests/bot/utils/test_redis_cache.py
@@ -44,22 +44,14 @@ class RedisCacheTests(unittest.IsolatedAsyncioTestCase):
         with self.assertRaises(RuntimeError):
             await bad_cache.set("test", "me_up_deadman")
 
-    def test_namespace_collision(self):
-        """Test that we prevent colliding namespaces."""
-        bob_cache_1 = RedisCache()
-        bob_cache_1._set_namespace("BobRoss")
-        self.assertEqual(bob_cache_1._namespace, "BobRoss")
-
-        bob_cache_2 = RedisCache()
-        bob_cache_2._set_namespace("BobRoss")
-        self.assertEqual(bob_cache_2._namespace, "BobRoss_")
-
     async def test_set_get_item(self):
         """Test that users can set and get items from the RedisDict."""
         test_cases = (
             ('favorite_fruit', 'melon'),
             ('favorite_number', 86),
-            ('favorite_fraction', 86.54)
+            ('favorite_fraction', 86.54),
+            ('favorite_boolean', False),
+            ('other_boolean', True),
         )
 
         # Test that we can get and set different types.
diff --git a/tests/helpers.py b/tests/helpers.py
index 13283339b..facc4e1af 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -5,7 +5,7 @@ import itertools
 import logging
 import unittest.mock
 from asyncio import AbstractEventLoop
-from typing import Iterable, Optional
+from typing import Callable, Iterable, Optional
 
 import discord
 from aiohttp import ClientSession
@@ -26,6 +26,24 @@ for logger in logging.Logger.manager.loggerDict.values():
     logger.setLevel(logging.CRITICAL)
 
 
+def autospec(target, *attributes: str, **kwargs) -> Callable:
+    """Patch multiple `attributes` of a `target` with autospecced mocks and `spec_set` as True."""
+    # Caller's kwargs should take priority and overwrite the defaults.
+    kwargs = {'spec_set': True, 'autospec': True, **kwargs}
+
+    # Import the target if it's a string.
+    # This is to support both object and string targets like patch.multiple.
+    if type(target) is str:
+        target = unittest.mock._importer(target)
+
+    def decorator(func):
+        for attribute in attributes:
+            patcher = unittest.mock.patch.object(target, attribute, **kwargs)
+            func = patcher(func)
+        return func
+    return decorator
+
+
 class HashableMixin(discord.mixins.EqualityComparable):
     """
     Mixin that provides similar hashing and equality functionality as discord.py's `Hashable` mixin.
@@ -208,6 +226,10 @@ class MockRole(CustomMockMixin, unittest.mock.Mock, ColourMixin, HashableMixin):
         """Simplified position-based comparisons similar to those of `discord.Role`."""
         return self.position < other.position
 
+    def __ge__(self, other):
+        """Simplified position-based comparisons similar to those of `discord.Role`."""
+        return self.position >= other.position
+
 
 # Create a Member instance to get a realistic Mock of `discord.Member`
 member_data = {'user': 'lemon', 'roles': [1]}