diff --git a/public/styles/chat.css b/public/styles/chat.css
index fcbf9cd..96afdc0 100644
--- a/public/styles/chat.css
+++ b/public/styles/chat.css
@@ -137,11 +137,6 @@ header {
 		flex: 1;
 	}
 
-	#chatInputContainer.authorized > div {
-		display: flex;
-	}
-
-	/* Reversed visibility for unauthenticated */
 	#chatInputContainer > #unauthenticated {
 		display: flex;
 		justify-content: space-around;
@@ -181,14 +176,19 @@ header {
 			cursor: not-allowed;
 		}
 
-		#chatInputContainer.authorized > #unauthenticated {
+		#chatInputContainer.authorized > #unauthenticated,
+		#chatInputContainer.banned > #unauthenticated {
 			display: none;
 		}
 
 	#authenticated {
-		display: flex;
+		display: none;
 		flex-direction: column;
 	}
+		#chatInputContainer.authorized > #authenticated {
+			display: flex;
+		}
+
 		#chatUserAndInputContainer {
 			display: flex;
 			margin: 2px 10px;
@@ -269,7 +269,8 @@ header {
 				margin-right: 4px;
 			}
 
-			#chatButtons > *.minimal {
+			#chatButtons > *.minimal,
+			button.minimal {
 				margin-left: 0;
 				color: #999;
 				font-size:.9em;
@@ -282,6 +283,31 @@ header {
 				text-decoration: none;
 			}
 
+	#banned {
+		display: none;
+		text-align: center;
+		flex-direction: column;
+		background: #06060699;
+	}
+		#banned a,
+		#banned a:visited {
+			color: #09f;
+		}
+
+		#banned a:hover {
+			color: #3df;
+		}
+
+		#chatInputContainer.banned > #banned {
+			display: flex;
+		}
+
+		#banTitle {
+			padding-top: 4px;
+			font-size: 2em;
+			color: #e44;
+		}
+
 	input[type=number] {
 		max-width: 50px;
 		min-width: 30px;
diff --git a/src/client/chat/chat.js b/src/client/chat/chat.js
index 7c63483..a16a39c 100644
--- a/src/client/chat/chat.js
+++ b/src/client/chat/chat.js
@@ -46,51 +46,7 @@ domReady.then(() => {
 
 	// Check for former authentication
 	cookieData = Cookies.getJSON("user_data");
-
-	if (
-		// If there is former data, check if it is not outdated.
-		cookieData
-
-		// See if current date is later than origin date + expiration period
-		&& Date.now() < cookieData.access_granted + cookieData.expires_in * 1000
-	) {
-		// Request a fresh token
-		var xhr = new XMLHttpRequest();
-		xhr.onreadystatechange = function() {
-			if (this.readyState === 4 && this.status === 200) {
-				let response = JSON.parse(xhr.responseText);
-
-				if (response.authorized && response.refreshed && response.tokenBody) {
-					response.tokenBody.id = cookieData.id;
-					response.tokenBody.username = cookieData.username;
-					response.tokenBody.discriminator = cookieData.discriminator;
-					response.tokenBody.avatar = cookieData.avatar;
-					let days = (response.tokenBody.expires_in / 62400) - 0.1; // seconds to days minus some slack
-					Cookies.set("user_data", response.tokenBody, {
-						expires: days,
-						path: "/",
-						domain: window.location.hostname,
-						secure: config.ssl
-					});
-					cookieData = response.tokenBody;
-				}
-
-				// Redundant check as non-authorized requests are returned as a 400
-				if (response.authorized) {
-					onAuthorization(cookieData);
-				}
-			}
-		};
-		xhr.open("POST", "/chat", true);
-		xhr.setRequestHeader("Content-Type", "application/json; charset=utf-8");
-		xhr.send(
-			JSON.stringify({
-				"type": "refresh_token",
-				"id": cookieData.id,
-				"access_token": cookieData.access_token
-			})
-		);
-	}
+	checkAuthentication();
 
 	let lastMessageSent = Date.now();
 	let sendMessage = function(message) {
@@ -189,24 +145,25 @@ domReady.then(() => {
 	}, false);
 
 	// Make log out button functional
-	let chatButtonLogOut = document.getElementById("buttonLogOut");
-	chatButtonLogOut.addEventListener("click", function() {
-		if (confirm("Do you really wish to log out?")) {
-			Cookies.remove("user_data",
-				{
-					path: "/",
-					domain: window.location.hostname
+	for (let chatButtonLogOut of document.getElementsByClassName("buttonLogOut")) {
+		chatButtonLogOut.addEventListener("click", function() {
+			if (confirm("Do you really wish to log out?")) {
+				Cookies.remove("user_data",
+					{
+						path: "/",
+						domain: window.location.hostname
+					}
+				);
+
+				// Send to parent if applicable
+				if (inIframe()) {
+					window.top.postMessage(userState.AUTH_CHANGED, `${window.location.origin}/client`);
 				}
-			);
 
-			// Send to parent if applicable
-			if (inIframe()) {
-				window.top.postMessage(userState.AUTH_CHANGED, `${window.location.origin}/client`);
+				window.location.reload(true);
 			}
-
-			window.location.reload(true);
-		}
-	}, false);
+		}, false);
+	}
 });
 
 let authWindow;
@@ -224,9 +181,9 @@ function authenticationWindow() {
 window.addEventListener("message", receiveMessage, false);
 function receiveMessage(event) {
 	if (event.data && event.data.success && event.origin === window.location.origin) {
-		onAuthorization(event.data.response);
 		cookieData = Cookies.getJSON("user_data");
 		authWindow.close();
+		checkAuthentication();
 
 		// Send to parent if applicable
 		if (inIframe()) {
@@ -240,3 +197,55 @@ function onAuthorization(data) {
 	document.getElementById("userName").innerText = `${data.username}#${data.discriminator}`;
 	document.getElementById("chatInputContainer").className = "authorized";
 }
+
+function onBanned() {
+	document.getElementById("chatInputContainer").className = "banned";
+}
+
+function checkAuthentication() {
+	if (
+		// If there is former data, check if it is not outdated.
+		cookieData
+
+		// See if current date is later than origin date + expiration period
+		&& Date.now() < cookieData.access_granted + cookieData.expires_in * 1000
+	) {
+		// Request a fresh token
+		var xhr = new XMLHttpRequest();
+		xhr.onreadystatechange = function() {
+			if (this.readyState === 4 && this.status === 200) {
+				let response = JSON.parse(xhr.responseText);
+
+				if (response.authorized && response.refreshed && response.tokenBody) {
+					response.tokenBody.id = cookieData.id;
+					response.tokenBody.username = cookieData.username;
+					response.tokenBody.discriminator = cookieData.discriminator;
+					response.tokenBody.avatar = cookieData.avatar;
+					let days = (response.tokenBody.expires_in / 62400) - 0.1; // seconds to days minus some slack
+					Cookies.set("user_data", response.tokenBody, {
+						expires: days,
+						path: "/",
+						domain: window.location.hostname,
+						secure: config.ssl
+					});
+					cookieData = response.tokenBody;
+				}
+
+				if (response.authorized) {
+					onAuthorization(cookieData);
+				} else if (response.banned) {
+					onBanned();
+				}
+			}
+		};
+		xhr.open("POST", "/chat", true);
+		xhr.setRequestHeader("Content-Type", "application/json; charset=utf-8");
+		xhr.send(
+			JSON.stringify({
+				"type": "refresh_token",
+				"id": cookieData.id,
+				"access_token": cookieData.access_token
+			})
+		);
+	}
+}
diff --git a/src/server/chat/discord-manager.js b/src/server/chat/discord-manager.js
index 41afd8b..aff1f74 100644
--- a/src/server/chat/discord-manager.js
+++ b/src/server/chat/discord-manager.js
@@ -49,6 +49,18 @@ const discordManager = function() {
 			}, console.error);
 
 			this.client.on("error", console.error, console.error);
+
+			this.client.on("guildBanAdd", function(guild, user) {
+				log.info(`DISCORD: ${"Banned user".red} ${user.username}#${user.discriminator} (${user.id})`);
+				db.user.setBanState(true, user.id);
+			}, console.error);
+
+			this.client.on("guildBanRemove", function(guild, user) {
+				log.info(`DISCORD: ${"Unbanned user".green} ${user.username}#${user.discriminator} (${user.id})`);
+				db.user.setBanState(false, user.id);
+			}, console.error);
+
+
 			this.client.login(config.discord.botToken);
 
 			return socketChat;
@@ -151,21 +163,25 @@ const discordManager = function() {
 						let response = {
 							authorized: true,
 							refreshed: true,
+							banned: false,
 							tokenBody
 						};
 
 						res.send(response);
 					},
 					() => {
-						res.status(400).send({ authorized: false, refreshed: false });
+						res.status(400).send({ authorized: false, refreshed: false, banned: false });
 					});
 				} else if (this.db.user.idIsAuthenticated(req.body.id, req.body.access_token)) {
-					res.send({ authorized: true, refreshed: false });
+					res.send({ authorized: true, refreshed: false, banned: false });
+					return;
+				} else if (this.db.user.idIsBanned(req.body.id)) {
+					res.send({ authorized: false, refreshed: false, banned: true });
 					return;
 				}
 			}
 
-			res.status(400).send({ authorized: false, refreshed: false });
+			res.status(400).send({ authorized: false, refreshed: false, banned: false });
 		}
 	};
 }();
diff --git a/src/server/database/initializer.js b/src/server/database/initializer.js
index be9e5a3..78a8aad 100644
--- a/src/server/database/initializer.js
+++ b/src/server/database/initializer.js
@@ -1,7 +1,7 @@
 const log = require("../../log");
 
 module.exports = function(db) {
-	let _schemaVersion = 3;
+	let _schemaVersion = 4;
 
 	return {
 		_users: db.prepare(
@@ -15,6 +15,7 @@ module.exports = function(db) {
 				timestamp_refresh_last INTEGER,
 				time_refresh_expire INTEGER,
 				scope TEXT,
+				is_banned INTEGER,
 				stat_points_earned INTEGER,
 				stat_rounds_entered INTEGER,
 				stat_rounds_finished INTEGER,
diff --git a/src/server/database/users.js b/src/server/database/users.js
index edef580..4bcd8d4 100644
--- a/src/server/database/users.js
+++ b/src/server/database/users.js
@@ -6,12 +6,28 @@ module.exports = function(db, common) {
 			return !!this._idExists.get(id);
 		},
 
-		_idIsAuthenticated: db.prepare("SELECT access_token FROM users WHERE id = ?"),
+		_idIsAuthenticated: db.prepare("SELECT access_token, is_banned FROM users WHERE id = ?"),
 
 		idIsAuthenticated(id, access_token) {
 			if (this.idExists(id)) {
 				let row = this._idIsAuthenticated.get(id);
-				if (row && row.access_token == access_token) {
+				if (
+					row
+					&& row.access_token == access_token
+					&& row.is_banned !== 1
+				) {
+					return true;
+				}
+			}
+			return false;
+		},
+
+		_idIsBanned: db.prepare("SELECT is_banned FROM users WHERE id = ?"),
+
+		idIsBanned(id) {
+			if (this.idExists(id)) {
+				let row = this._idIsBanned.get(id);
+				if (row && row.is_banned === 1) {
 					return true;
 				}
 			}
@@ -113,6 +129,7 @@ module.exports = function(db, common) {
 				timestamp_refresh_last,
 				time_refresh_expire,
 				scope,
+				is_banned,
 				stat_points_earned,
 				stat_rounds_entered,
 				stat_rounds_finished,
@@ -122,7 +139,7 @@ module.exports = function(db, common) {
 				stat_marbles_not_finished,
 				stat_unique_levels_played,
 				timestamp_first_login
-			) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`
+			) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)`
 		),
 
 		insertNewUserEmbed(token_body, user_body, scope) {
@@ -144,6 +161,7 @@ module.exports = function(db, common) {
 				0,
 				0,
 				0,
+				0,
 				Date.now()
 			]);
 		},
@@ -155,6 +173,7 @@ module.exports = function(db, common) {
 				username,
 				discriminator,
 				avatar,
+				is_banned,
 				stat_points_earned,
 				stat_rounds_entered,
 				stat_rounds_finished,
@@ -164,7 +183,7 @@ module.exports = function(db, common) {
 				stat_marbles_not_finished,
 				stat_unique_levels_played,
 				timestamp_first_login
-			) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?)`
+			) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)`
 		),
 
 		insertNewUserDiscord(user) {
@@ -181,10 +200,29 @@ module.exports = function(db, common) {
 				0,
 				0,
 				0,
+				0,
 				Date.now()
 			]);
 		},
 
+		// bans
+		_setBanState: db.prepare(
+			`UPDATE OR REPLACE users SET
+				is_banned = ?
+			WHERE
+				id = ?`
+		),
+
+		setBanState(banState, id) {
+			if (this.idExists(id)) {
+				banState = banState ? 1 : 0; // Convert to integer since SQLite3 does not support the boolean type.
+				this._setBanState.run([
+					banState,
+					id
+				]);
+			}
+		},
+
 		// stat_points
 		_incrementUserPoints: db.prepare(
 			`UPDATE OR ABORT
diff --git a/src/server/network/sockets.js b/src/server/network/sockets.js
index 3e18652..0051676 100644
--- a/src/server/network/sockets.js
+++ b/src/server/network/sockets.js
@@ -87,23 +87,25 @@ const setupChat = function(db, chatWebhook) {
 			return;
 		}
 
-		let row = db.user.getUserDetailsById(message.id);
-		if (row && row.access_token == message.access_token) {
-			messages.parse(message.content, message.id, row.username);
+		if (db.user.idIsAuthenticated(message.id, message.access_token)) {
+			let row = db.user.getUserDetailsById(message.id);
+			if (row) {
+				messages.parse(message.content, message.id, row.username);
 
-			chatWebhook.send(message.content, {
-				username: row.username,
-				avatarURL: `https://cdn.discordapp.com/avatars/${message.id}/${row.avatar}.png`,
-				disableEveryone: true
-			});
+				chatWebhook.send(message.content, {
+					username: row.username,
+					avatarURL: `https://cdn.discordapp.com/avatars/${message.id}/${row.avatar}.png`,
+					disableEveryone: true
+				});
 
-			chatSocketManager.emit(JSON.stringify({
-				username: row.username,
-				discriminator: row.discriminator,
-				content: message.content
-			}));
-		} else {
-			log.warn("User ID and access token mismatch!", row);
+				chatSocketManager.emit(JSON.stringify({
+					username: row.username,
+					discriminator: row.discriminator,
+					content: message.content
+				}));
+			} else {
+				log.warn("User ID and access token mismatch!", row);
+			}
 		}
 	});
 
diff --git a/templates/chat.mustache b/templates/chat.mustache
index fddd1ee..e078f9a 100644
--- a/templates/chat.mustache
+++ b/templates/chat.mustache
@@ -64,12 +64,17 @@
 					<i class="icon-right-big" id="buttonSend"></i>
 				</div>
 				<div id="chatButtons">
-					<button id="buttonLogOut" class="minimal"><i class="icon-logout"></i> log out</button>
+					<button class="buttonLogOut minimal"><i class="icon-logout"></i> log out</button>
 					{{#invitelink}}<a href="{{invitelink}}" target="_blank" class="minimal"><i class="icon-link-ext"></i> join server</a>{{/invitelink}}
 					<div class="flexSpacer">&nbsp;</div>
 					<button id="buttonMarble">!marble</button>
 				</div>
 			</div>
+			<div id="banned">
+				<div id="banTitle">You are banned</div>
+				<p>If you wish to appeal this decision, <a href="/contact">contact us</a>.</p>
+				<button class="buttonLogOut minimal"><i class="icon-logout"></i> log out</button>
+			</div>
 		</div>
 	</body>
 </html>