ip/user banning Emergency?

[TMM-TT]

We have a few users that in some reason doesn't like us that always coming back after a while when they got banned. They are sneaking around and doesn't do anything except for annoying us. If we could prevent that banned users can't reach the site at all, they won't be able to register new accounts either. The trolltracker linked above got a new function yesterday that works like ipbanning, but instead of trying to track down a banned user and ban their ip's, it checks users/guest against the built in banlist. If there's a match, it doesn't matter if the user is a guest or logged in - they can't see anything except "You're banned" and why they were banned.