In
Internet slang, a
troll (
/ˈtroʊl/,
/ˈtrɒl/) is a person who sows discord on the Internet by starting arguments or upsetting people,[SUP]
[1][/SUP] by posting inflammatory,[SUP]
[2][/SUP]
extraneous, or
off-topic messages in an online community (such as a forum,
chat room, or blog) with the deliberate intent of provoking readers into an
emotional response[SUP]
[3][/SUP] or of otherwise disrupting normal on-topic discussion.[SUP]
[4][/SUP]
That's from Wikipedia, always a reliable source
Personally, except in flagrant cases, I think one man's troll might be another's troubled soul.