Being a prick on the internet because you can. Typically unleashing one or more cynical or sarcastic remarks on an innocent by-stander, because it's the internet and, hey, you can.

trolling is the act of stating completely true facts inside a forum or thread. The act of trolling is often looked down upon because other people don't like it when they are told they are wrong. A troll is simply some one who states true facts in the attempt to make the world a better place

Trolling is the act of purposefully antagonizing other people on the internet, generally on message boards. When done in a moderated internet community, this can result in banning. When done to uptight people such as fundies, this can result in hilarity.

Not cyberbullying.

Some people do horrible things that can make others depressed or even commit suicide. They call themselves trolls, and the media believes them, but they aren't trolls. They are cyberbullies and horrible people. Good trolls can make both people laugh in the end.

Hunting for trolls.

Trollers hang around under bridges with troll guns at night (since trolls turn to stone in daylight), in the hope of bagging a troll head as a trophy.

As a VERY endangered (i.e. nonexistent) species, trolls are protected by law, and trolling is therefore illegal.

Trolling is the term derived from the word "troll," which indicates trailing a fish along a baited line. In modern culture, trolling refers to hitting on guys when you are out, by baiting them with a little information about yourself or a flirty comment, and then playing hard to get. By planting the "bait," a girl will subsequently "troll" and find herself surrounded by a whole crowd of boys.

The act of trolling is an art-form, generally reserved for hot chicks out at a bar and/or club. However, it is possible to troll in all locations, such as the library or a coffee-shop, though that is a skill reserved for only the most talented individuals.

Note: Not to be confused with the noun "troll" (an ugly chick) or spamming message board (whoever does that cannot certainly cannot actually go trolling).

Responding through short, unhelpful, and often antagonistic means, or performing acts with the intent of getting a rise from people so it can be posted on youtube later. No longer bound to the confines of the internet.