I have a suggestion and I'm not sure if it's currently being done or not. When a new member joins this site and makes a new members thread, their IP should be checked by a moderator to be sure it's not a "repeat offender" or a troll coming back under a new nick.
We've saw it all too many times. Someone gets banned, waits a week, then comes back under a new name only to be banned again. This may be a way to put an end to it.