Speaking of Trolls, I feel the need to share this story:
A few weeks back, on another Gaming Forum I frequent, we had an individual come into our midst acting pretty nonchalant and normal at first. He began by just going back and forth on the Edition Wars debate that's pretty much still ongoing at this site. The nice thing about this site, though, is that we're all pretty mature on the discussions and it rarely devolves into name-calling (mostly because the mods are very active and will stomp out and lock threads pretty quick if flames rise).
He began by 'debating' us that we were mis-informed on 4th Edition. One of the best threads he created was a simple question on what we considered to be Ret-Cons regarding the changes after the Spellplague in the Forgotten Realms setting. We responded with some examples of what we considered ret-cons (elves now being eladrin, etc.) but his response was that those were ret-cons in his eyes. Of course, this led to more and more arguing over not just what was done to the Realms, but what the definition of a Ret-con was.
At every step, he told us we were wrong. And he stopped being nice, which, by internet law, forces others to take off the gloves. Well, long story short, it became that when every he appeared in a thread, a few of us (yes, I was included) simply replied with 'Begone Troll'.
The real interesting part is that I noticed that the avatar name he chose for the site bore a resemblance to a recognizable person in the game industry. I had pm'd a couple of the other posters that he had singled out and, sure enough, we discovered that he is an industry insider working for some Beach Sorcerers. The one person I was in contact with called him on it through a PM.
Next thing you know, he makes a public apology to that person, then disappears off the boards. :D