Right off the bat: by my definition, trolling does not mean threatening or verbally assaulting someone online
Now that we got that sorted:
I know a few internet trolls (people who pretend to be stupid to make a self-appointed sophisticated person respond to them in a know-it-all manner, only to deny everything the person had to say afterwards) and I believe that it is a way for them to be foolish for a moment, to be inconsistent for once. They go online, troll some people, and then they go offline and are perfectly normal, disciplined and nice again.
ON THE OTHER HAND, people who are overly correct, in every respect, online (be it in forums, or wherever) are often... you guessed it... pretty unpleasant people to be around, in real life. (to give you an example real quick: you are like:"Yes! I love this song!" and then the other one is like:"I really don't see why you would like this song." ... if you aren't one yourself you might know what I mean by now.)
Anyway...what I'm trying to say is that a "troll" has more potential to be a fun guy than a person just like I described in the paragraph above.
What do you guys think?!
ps: I will probably update this and be a little more specific about what I'm talking about, but I just had to get this thought out there.