I'm not really sure this should be called trolling, it's more just harassing/bullying/trespassing. When I think of trolling, at least when it's done well, it's more taking on overly self serious people to get a funny reaction (even if it's obnoxious). It's like a cousin of pranking, it shouldn't be cruel. There can be cruel pranks of course, but that's not the fundamental nature. Like Ken M leaving a really oblivious comments on facebook, or Something Awful forum members joining an online game chatroom as a weird cult ("the path is grey" :D ). Weird, funny, mostly harmless. I mean things like that are obnoxious sometimes but they can be funny and work as satire or social commentary. There's no cleverness to this.

(probably the wrong thing to write on HN since this place is uh not known for its sense of humor)