One who posts content on a forum to make people extremely angry, and possibly start a flame war. In recent years however, trolling has greatly evolved, spawning entire categories of ways to piss people off. Trolls are also largely shaped by their internet environment, such that on forums, they may merely "flame", but on other sites such as anonymous chat sites (such as omegle) they go to great lengths to bother people. These include asking them if they are turtles, like fishsticks, or saying "India". On anonymous video chatting sites, they go to even greater lengths to bother people, making up entire songs and others to bother people. Many examples of trolling can be found on Art of Trolling, a site hosted by the cheezburger network.
Forum troll: Your a faggot so i dont have to aknolege u!111!!!!!
Chat troll: My good sir, it appears that there is a monstrous turtle behind you
Video chat troll: I'm going to dress like a nude girl from behind, but turn around and freak people out when I'm really a guy!