I think the "sociology" of internet forums would make for an interesting study.

I'm on a photography forum, and there is one guy there who has two accounts. That's against forum rules, but I'm not sure how hard that is to detect. Anyway, the guy has an unpopular viewpoint and he uses his second account to reinforce his first account any time someone disagrees. "You're exactly right, Joe, that's how I do it too!". He can use one or the other account to argue with the other members and then he brings in the other account just to agree with the first. He also has a third and a fourth account he uses once in a great while if the arguments start to get too heated for the first too. The irony being, it is obvious to everyone that it is all the same guy because he uses some weird terminology and always posts in the same odd style of hitting the "return" key at the end of each sentence. So anyone who has been around awhile can spot all the guys accounts right away.