Being a douche 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. The art of deliberately, cleverly, and secretly pissing people off, usually via the internet, using dialogue. Trolling does not mean just making rude remarks: Shouting swear words at someone doesn't count as trolling; it's just flaming, and isn't funny.
Wow you're trolling again, doesn't surprise me.
Please stop trolling.