I think they basically watch for the racist stuff. That is pretty much an instant ban. As for calling fighters names they let alot of that go but i think if it got bad they would put a stop to it.
Unfortunately stupid isn't a crime but it does last forever. So i kinda feel bad for people like britneyspearsguy and mmapimp. They will be forever lost in the world of stupidity. Although i did hear some scientist in Germany or something has developed a pill that helps with memory loss and they are calling it an anti-stupid pill. I know a few people that could buy it by the case and hopefully at least begin to make sense.