PurpBot

PurpBot is great when it comes to protecting servers from raids. If you're the owner/admin, simply type +lockdown and only admins will be able to type in the channel where you've executed the command. Type +unlock if you'd like to lift the lockdown. PurpBot also comes with hackbanning which is banning a user who isn't in the server. Type +hban (the user's ID) and they won't be able to join the server.