This has become big news today. Back in January a student beat up a classmate for spreading rumors about her. A group of friends looked on and filmed it, and ultimately uploaded it and the girl's personal information to the internet. Here it is
About a year ago, Gusts of Popular Feeling looked at similar cases of bullying and humiliation in Korean schools, a post which leads off with the story of Korean students in New Zealand who tortured a classmate for an hour.
* When this gets pulled again, just run a Naver search to get to one of the other copies.