I've seen a few people being accused of being a troll, but on back-tracking threads they didn't do anything to be called such. There are those trolls who specialise in accusing people of being a troll for no other reason than their own sick sense of humour; in other words, falsely accuse someone of being a troll.
Anyway. Internet troll, or 'trolling'
... a person who sows discord on the Internet by starting arguments or upsetting people, by posting inflammatory, extraneous, or off-topic messages in an online community (such as a newsgroup, forum, chat room, or blog) with the intent of provoking readers into an emotional ...
Trolls work overtime to do it, think some of them are paid trolls attempting to disrupt people from forming their own groups for the purpose of communicating about issues in life that need to be dealt with in society and politically.
@cherokeepatti: Trolling is an art form, as is hacking and can be considered a 'profession' in their own right. In small communities such as the likes of this place, it's sometimes hard to distinguish the legitimacies of what's written or even the truth behind accusations.
They constantly want to provoke arguments or cause fights between other members or get other members kicked off sites too. Go into trivial details like someone's spelling when they are losing an argument.