I think there are a lot of reasons for trolling...
You can troll because:
1) You are bored
2) You are a teen reaffirming your masculinity (i.e. "childlish" game bashing)
3) You know THE truth, and you need to show it to evereybody
4) You are punked in class and it's a way to liberate yourself
5) Nearly anyone knows you for real in the internet, so you can do somethings you wouldn't do in the real life
6) It's fun
And I'm sure I missed some more...







