Hmm, I happen to think the T word get's thrown around far too lightly these days, and that it's not one particular thing that makes someone a troll, but more a pattern of behavior. To give one example, I'm a member of another forum made up of pizza delivery drivers, the forum is advertised as a place that we can let off steam about our jobs off the clock. Periodically, someone will show up and post something to the effect of "you're all a bunch of losers, if your job sucks so much why don't you quit?", and if we ever get a second post, it's usually something like "you guys are just mad cause I totally just pwned the board, etc etc". THAT, is a troll, someone who's sole purpose in being there is too piss everyone off. To give another example, through that same pizza board I'm a member of a forum owned by a pizza restaurant magazine that's mostly populated by shop owners, where I provide an employee's perspective on running a pizzeria, and am often accused of trolling there because my opinions often clash with the rest of the forum members'. Not the same thing, I'm not there for the purpose of pissing people off, even though I'm posting in hostile territory and things often get combative. I think trolls are kind of like obscenity, you can't really lay down specifics, but you know one when you see one.
_________________
Your boos mean nothing, I've seen what makes you cheer.
- Rick Sanchez