There are two uses of the word troll. I think you are using the less common of the two.

Yeah, trolling can be used to describe people who lurk 24-7 and hop right on posts all day long.

More often, trolling is about the attitude. Is somebody just laying down flamebait all day long?

Are they pointing out the negative parts of what people say and ignoring their valid responses?

Mostly people troll either for self satisfaction. i.e., making easy jokes and doing things 'for the lulz.' Otherwise, they may be working on some type of imfamous fourm reputation that the kids all think is so cool.

Meh. Trolls have their place. Some people take it too far. Some people aren't trolling. They are just assholes. Trolls are almost always trying to be funny. Often at the expense of other posters.

/wall of text

//$.02

In that linked thread, I think that Trigeminal just didnt get what the second poster was saying. Although he was doing it in a snarky way ("FIFY"), he was actually agreeing with the OP. So yeah... I think that was either a misunderstanding or he was using the first definition I spoke about above.

EDIT: What is up with the auto linking user name bullshit? Ive never seen it work correctly.

I remember this very question being asked on several forums I've posted on. I came across a medical diagram breaking down the inner workings of a Troll's brain so that we might better understand it.