[KenWittlief]

the term 'troll' is a spin-off of a method of fishing. You pull a piece of bait on a hook behind a slow moving boat, trying to get a fish to bite: Trolling.

Trolling on a website is throwing out some comment that you know will start an argument or flame war. The troll doesn't really care anything about the thing being discussed, he just wants to torque someones nose and see if any fish will go after his bait.