diff --git a/src/common/channel.js b/src/common/channel.js
index d8175ce..376bdf3 100644
--- a/src/common/channel.js
+++ b/src/common/channel.js
@@ -17,7 +17,7 @@ export const validateSubreddit = (name) => {
   return !!name.match(/^[A-Za-z0-9][A-Za-z0-9_]{2,20}$/i);
 };
 
-export const validateUsername = (name) => name.match(/^[\w-]{3,20}/);
+export const validateUsername = (name) => !!name.match(/^[\w-]{3,20}$/);
 
 export const validateChannel = (channel) => {
   if (!channel) {
diff --git a/src/server/packet/add-favorite.js b/src/server/packet/add-favorite.js
index 879b30c..f8f8337 100644
--- a/src/server/packet/add-favorite.js
+++ b/src/server/packet/add-favorite.js
@@ -1,10 +1,15 @@
+import {validateChannel} from '~/common/channel';
 import AddFavorite from '~/common/packets/add-favorite.packet';
 
-import {allModels} from '~/server/models/registrar';
+import ValidationError from './validation-error';
 
 export default {
   Packet: AddFavorite,
-  validator: async () => true,
+  validator: async ({data: channel}) => {
+    if (!validateChannel(channel)) {
+      throw new ValidationError({code: 400, reason: 'Malformed channel'});
+    }
+  },
   responder: async (packet, socket) => {
     const {req} = socket;
     await req.user.createFavorite({channel: packet.data});
diff --git a/src/server/packet/add-friend.js b/src/server/packet/add-friend.js
index 5da784a..a8b5379 100644
--- a/src/server/packet/add-friend.js
+++ b/src/server/packet/add-friend.js
@@ -10,10 +10,10 @@ export default {
   limiter: {points: 20, duration: 60},
   validator: async ({data: {nameOrStatus}}) => {
     if (!validateUsername(nameOrStatus)) {
-      throw new ValidationError('Invalid username');
+      throw new ValidationError({code: 400, reason: 'Malformed username'});
     }
   },
-  responder: async (packet, socket) => {
+  responder: async ({data: {nameOrStatus}}, socket) => {
     const {req} = socket;
     const {
       Friendship,
@@ -21,8 +21,8 @@ export default {
     } = allModels();
     const adderId = req.user.id;
     const user = (
-      await User.findOne({where: {redditUsername: packet.data.nameOrStatus}})
-      || await User.create({redditUsername: packet.data.nameOrStatus})
+      await User.findOne({where: {redditUsername: nameOrStatus}})
+      || await User.create({redditUsername: nameOrStatus})
     );
     const addeeId = user.id;
     let friendship = await Friendship.findOne({where: {adderId: addeeId, addeeId: adderId}});
diff --git a/src/server/packet/block.js b/src/server/packet/block.js
index 9927d79..6432fd2 100644
--- a/src/server/packet/block.js
+++ b/src/server/packet/block.js
@@ -7,9 +7,16 @@ import {allModels} from '~/server/models/registrar';
 
 import {removeFavoritedUser} from './remove-favorite';
 
+import ValidationError from './validation-error';
+
 export default {
   Packet: Block,
-  validator: async () => true,
+  validator: async ({data: id}) => {
+    const {User} = allModels();
+    if (!await User.count({where: {id}})) {
+      throw new ValidationError({code: 400, reason: 'No such user'});
+    }
+  },
   responder: async (packet, socket) => {
     const {req} = socket;
     const id = packet.data;
diff --git a/src/server/packet/join.js b/src/server/packet/join.js
index 2459278..d244fcf 100644
--- a/src/server/packet/join.js
+++ b/src/server/packet/join.js
@@ -3,6 +3,7 @@ import {promisify} from 'util';
 
 import {ServerSocket} from '@avocado/net/server/socket';
 
+import {validateChannel} from '~/common/channel';
 import Join from '~/common/packets/join.packet';
 
 import {
@@ -10,6 +11,8 @@ import {
   channelUsers,
 } from '~/server/entry';
 
+import ValidationError from './validation-error';
+
 export const userJoin = async (channel, socket) => {
   const userId = '/r/anonymous' === channel ? 0 : socket.handshake.userId;
   const users = await channelUsers(socket.handshake, channel);
@@ -21,10 +24,13 @@ export const userJoin = async (channel, socket) => {
 
 export default {
   Packet: Join,
-  validator: async () => true,
-  responder: async (packet, socket) => {
+  validator: async () => {
+    if (!validateChannel()) {
+      throw new ValidationError({code: 400, reason: 'Malformed channel'});
+    }
+  },
+  responder: async ({data: channel}, socket) => {
     const {req} = socket;
-    const {channel} = packet.data;
     await userJoin(channel, socket.socket);
     return channelState(req, channel);
   },
diff --git a/src/server/packet/leave.js b/src/server/packet/leave.js
index 707298c..acc458b 100644
--- a/src/server/packet/leave.js
+++ b/src/server/packet/leave.js
@@ -1,10 +1,13 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
 import {promisify} from 'util';
 
+import {validateChannel} from '~/common/channel';
 import Leave from '~/common/packets/leave.packet';
 
 import {channelUserCounts} from '~/server/entry';
 
+import ValidationError from './validation-error';
+
 export const userLeave = async (channel, socket) => {
   const userId = '/r/anonymous' === channel ? 0 : socket.req.userId;
   await promisify(socket.leave.bind(socket))(channel);
@@ -16,9 +19,10 @@ export const userLeave = async (channel, socket) => {
 
 export default {
   Packet: Leave,
-  validator: async () => true,
-  responder: async (packet, socket) => {
-    const {channel} = packet.data;
-    return userLeave(channel, socket);
+  validator: async () => {
+    if (!validateChannel()) {
+      throw new ValidationError({code: 400, reason: 'Malformed channel'});
+    }
   },
+  responder: async ({data: channel}, socket) => userLeave(channel, socket),
 };
diff --git a/src/server/packet/message.js b/src/server/packet/message.js
index 34befe1..d28407f 100644
--- a/src/server/packet/message.js
+++ b/src/server/packet/message.js
@@ -1,19 +1,28 @@
 import {v4 as uuidv4} from 'uuid';
 
-import {parseChannel} from '~/common/channel';
+import {parseChannel, validateChannel} from '~/common/channel';
 import Message from '~/common/packets/message.packet';
 
 import {allModels} from '~/server/models/registrar';
 
+import ValidationError from './validation-error';
+
 export default {
   Packet: Message,
   limiter: {points: 10, duration: 15},
-  validator: async () => true,
-  responder: async (packet, socket, fn) => {
+  validator: async ({data: {channel, message}}) => {
+    if (!validateChannel(channel)) {
+      throw new ValidationError({code: 400, reason: 'Malformed channel'});
+    }
+    if (message.length > 1024) {
+      throw new ValidationError({code: 400, reason: 'Your message was a bit too long'});
+    }
+  },
+  responder: async ({data}, socket) => {
     const {req} = socket;
     const {pubClient} = req.adapter;
     const {User} = allModels();
-    const {channel, message} = packet.data;
+    const {channel, message} = data;
     const {name, type} = parseChannel(`/chat${channel}`);
     const other = await User.findOne({where: {redditUsername: name}});
     const owner = '/r/anonymous' === channel ? 0 : req.userId;
@@ -26,7 +35,7 @@ export default {
     const key = `${serverChannel}:messages:${uuid}`;
     ('u' === type ? [`/user/${other.id}`, `/user/${req.userId}`] : [channel]).forEach((room) => (
       socket.to(room, new Message({
-        ...packet.data,
+        ...data,
         channel: 'r' === type
           ? channel
           : `/u/${username === room.substr(3) ? name : username}`,
diff --git a/src/server/packet/remove-favorite.js b/src/server/packet/remove-favorite.js
index c31672e..9bf6f44 100644
--- a/src/server/packet/remove-favorite.js
+++ b/src/server/packet/remove-favorite.js
@@ -1,34 +1,37 @@
+import {validateChannel} from '~/common/channel';
 import RemoveFavorite from '~/common/packets/remove-favorite.packet';
 
 import {allModels} from '~/server/models/registrar';
 
+import ValidationError from './validation-error';
+
 export const removeFavoritedUser = async (socket, user, other) => {
   const {Favorite} = allModels();
-  const favorites = await user.getFavorites();
-  const toRemove = favorites.find(({channel}) => channel === `/u/${other.redditUsername}`);
-  if (toRemove) {
-    await Favorite.destroy({
-      where: {
-        id: toRemove.id,
-      },
-    });
+  const favorite = await Favorite.findOne(
+    {where: {channel: `/u/${other.redditUsername}`, user_id: user.id}},
+  );
+  if (favorite) {
+    await Favorite.destroy({where: {id: favorite.id}});
     socket.to(`/user/${user.id}`, new RemoveFavorite(`/u/${other.redditUsername}`));
   }
 };
 
 export default {
   Packet: RemoveFavorite,
-  validator: async () => true,
+  validator: async ({data: channel}, {req: {user}}) => {
+    const {Favorite} = allModels();
+    if (!validateChannel()) {
+      throw new ValidationError({code: 400, reason: 'Malformed channel.'});
+    }
+    if (0 === await Favorite.count({where: {user_id: user.id, channel}})) {
+      throw new ValidationError({code: 400, reason: 'No such favorite existed.'});
+    }
+  },
   responder: async (packet, socket) => {
     const {req} = socket;
     const {Favorite} = allModels();
-    const favorites = await req.user.getFavorites();
-    const toRemove = favorites.find(({channel}) => channel === packet.data);
-    await Favorite.destroy({
-      where: {
-        id: toRemove.id,
-      },
-    });
+    const favorite = await Favorite.findOne({where: {channel: packet.data, user_id: req.user.id}});
+    await Favorite.destroy({where: {id: favorite.id}});
     socket.to(`/user/${req.userId}`, packet);
   },
 };
diff --git a/src/server/packet/remove-friend.js b/src/server/packet/remove-friend.js
index 0818595..7b580f2 100644
--- a/src/server/packet/remove-friend.js
+++ b/src/server/packet/remove-friend.js
@@ -6,12 +6,26 @@ import {allModels} from '~/server/models/registrar';
 
 import {removeFavoritedUser} from './remove-favorite';
 
+import ValidationError from './validation-error';
+
 export default {
   Packet: RemoveFriend,
-  validator: async () => true,
-  responder: async (packet, socket) => {
+  validator: async ({data: id}, {req: {userId}}) => {
+    const {Friendship} = allModels();
+    const hasFriendship = !!await Friendship.count({
+      where: {
+        [Op.or]: [
+          {[Op.and]: [{addeeId: userId}, {adderId: id}]},
+          {[Op.and]: [{addeeId: id}, {adderId: userId}]},
+        ],
+      },
+    });
+    if (!hasFriendship) {
+      throw new ValidationError({code: 400, reason: 'Malformed friendship.'});
+    }
+  },
+  responder: async ({data: id}, socket) => {
     const {req} = socket;
-    const id = packet.data;
     const {Friendship, User} = allModels();
     await Friendship.destroy({
       where: {
@@ -24,7 +38,9 @@ export default {
     socket.to(`/user/${id}`, new RemoveFriend(req.userId));
     socket.to(`/user/${req.userId}`, new RemoveFriend(id));
     const user = await User.findByPk(id);
-    removeFavoritedUser(socket, user, req.user);
-    removeFavoritedUser(socket, req.user, user);
+    return Promise.all([
+      removeFavoritedUser(socket, user, req.user),
+      removeFavoritedUser(socket, req.user, user),
+    ]);
   },
 };
diff --git a/src/server/packet/unblock.js b/src/server/packet/unblock.js
index 8cb85db..42a5596 100644
--- a/src/server/packet/unblock.js
+++ b/src/server/packet/unblock.js
@@ -2,15 +2,28 @@ import Unblock from '~/common/packets/unblock.packet';
 
 import {allModels} from '~/server/models/registrar';
 
+import ValidationError from './validation-error';
+
 export default {
   Packet: Unblock,
-  validator: async () => true,
-  responder: async (packet, socket) => {
+  validator: async ({data: blocked}, {req: {userId}}) => {
+    const {Block: BlockModel} = allModels();
+    const hasBlock = !!await BlockModel.count({
+      where: {
+        blocked,
+        user_id: userId,
+      },
+    });
+    if (!hasBlock) {
+      throw new ValidationError({code: 400, reason: "Wasn't blocking."});
+    }
+  },
+  responder: async ({data: blocked}, socket) => {
     const {req} = socket;
     const {Block: BlockModel} = allModels();
     await BlockModel.destroy({
       where: {
-        blocked: packet.data,
+        blocked,
         user_id: req.userId,
       },
     });
diff --git a/src/server/packet/validation-error.js b/src/server/packet/validation-error.js
index 1e5d16e..3c2798f 100644
--- a/src/server/packet/validation-error.js
+++ b/src/server/packet/validation-error.js
@@ -1 +1,9 @@
-export default class ValidationError extends Error {}
+export default class ValidationError extends Error {
+
+  constructor(...args) {
+    const [payload, ...after] = args;
+    super(...after);
+    this.payload = payload;
+  }
+
+}
diff --git a/src/server/sockets.js b/src/server/sockets.js
index e91c45f..fc04517 100644
--- a/src/server/sockets.js
+++ b/src/server/sockets.js
@@ -10,6 +10,7 @@ import createLimiter from './limiter';
 import * as PacketHandlers from './packet';
 import {userJoin} from './packet/join';
 import {userLeave} from './packet/leave';
+import ValidationError from './packet/validation-error';
 import passport from './passport';
 import createRedisClient from './redis';
 import session from './session';
@@ -72,6 +73,10 @@ export function createSocketServer(httpServer) {
         fn(undefined, await responder(packet, socket));
       }
       catch (error) {
+        if (error instanceof ValidationError) {
+          fn(error.payload);
+          return;
+        }
         if (error instanceof Error) {
           fn({code: 500});
           throw error;