There are some people who play games because they're fun. There are other people who play games because winning against real people is very satisfying. Then there are those people who define "winning" in this context as "inciting red-hot rage". I work with one of those people, and I do not play games anywhere near him.
Mokalus of Borg
PS - It's called "griefing".
PPS - I don't understand it, though.