http://www.salon.com/2013/07/19/ever..._trolling_now/

If everyone is a troll, maybe no one is.
In the past few years, accusations of “trolling” have flown across the Internet fast and furious; recently, the targets have included a New York Times feature about the popularity of chopped salads, just about everything Vice does, and a cover of Rolling Stone featuring Dzhokhar Tsarnaev.
But for a word that’s tossed around so frequently, its meaning seems to evaporate into air when grasped at. Trolling is bad. Trolling provokes a reaction, usually negative. Trolling is apparently quite easy to do. But, if only to better gird one’s own defenses against it — what is trolling?
“I think that it started with a pretty clear definition — which is somebody who goes into a place that shares a particular ideology and says something they don’t believe just to get a reaction,” said Sady Doyle, a feminist blogger and staff writer for In These Times.
“Originally, it was, like, racist Reddit kids going into r/blackgirls — that was old-school trolling, a very specific online behavior,” said Matt Buchanan, a tech blogger for the New Yorker, referring to the popular message board and clearinghouse for human pathologies in which racist, sexist or homophobic vitriol flowed freely. On Reddit, clearly defined groups sort themselves according to demographics, identity and ideology — a troll would attempt to disrupt these groups, and order as normal. Trolls, as classically defined, could insert themselves into any number of milieus; the classic New York Times Magazine piece documenting the state of the troll in 2008 recorded instances like self-defined trolls hacking the Epilepsy Foundation’s website in order to fill it with flashing lights, triggers for epileptics. As an action designed to harm and upset a specific group of people, it wasn’t exactly a newspaper piece about salad.