I think this is very important. I hace been a moderator to a major Greek forum. The hardest thing to handle was malicious users that posted normal topics with normal Titles.
After a while they edited the title and body with ads. This was hard to find and fix.
Also we had a user that went crazy, deleted 1000+ of his posts and left.
So we used some options of the php forum we used, that had timed editing if topics/titles and delete.