Probably the same reason as all the others, being cocky and thinking they are better then everyone else (I.E. Being a general troll). I think out of all the times people have been banned, only once was there one I didn't agree with. Can't be done with people like that. . . 
It depends on the infraction. If it's general trolling the member is often given a warning but if anyone breaks the trading rules or thumbs their nose at an Amibay moderator... "Hasta la vista baby"! :uzi:
