It's a shame that trolls are common enough for there to be a name for them.

In Internet terminology, a troll is often someone who comes into an established community such as an online discussion forum, and posts inflammatory, rude, repetitive or offensive messages designed intentionally to annoy or antagonize the existing members or disrupt the flow of discussion, including the personal attack of calling others trolls. Often, trolls assume multiple aliases, or sock puppets.

Trolls often attempt to compensate for serious personal deficiencies, such as never advancing beyond Vice President of Paperclips or Hall Monitor, by manufacturing relationships with well-known individuals in an attempt to increase personal stature.  Most trolls are homosexual and live with their mothers.

Do not feed the trolls...