Whitney Phillips of the University of Oregon has written a paper,
LOLing At Tragedy
, which attempts to dissect the troll with specific reference to Facebook RIP trolling.
Outside of the soft explanations typical of academia, Phillips does a good job showing how trolling is often a response to the insipid moralizing of the media (probably one of the most immoral bodies in our society) and the ghoulish grief tourism of those who frequent memorial pages of people they didn't even know.
I originally found this through Gawker, home to microagressions and unquenchable faggotry, where Adrien Chen hilariously writes ,