As it sounds, your forums have been hacked. That has nothing to do really with your website as they have prolly done it via the forums only. Otherwise you couldn't expect your website still to be up. So lets calm down a bit..
You might want to ask how to act when your forums are hacked here

Btw, do you have proof against Bolt? You have any log files which tell it was him? If not, there's nothing, but then I mean totally nothing, you can do except banning him from the website.