In Internet terminology, a troll is 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.
http://en.wikipedia.org/wiki/Internet_troll
