Real trolls never last on here, so I don’t see this as being a major issue on fluther. On some other Q & A sites however, this may be a much bigger issue. To me it is motivations which determines the difference between stating an unpopular opinion vs trolling. One is passionate about their posts, while the other is just looking for trouble.
Well getting back to answering your question I don’t feel that there is much of a difference (if any) between an online troll (the real thing) and an offline a-hole. It is easier to stir the pot online, and safer for them due to anonymity.