When I was in school sometimes the teachers would talk to the class about bullying and why it is wrong. We never had any of those bullying campaigns but the teachers sometimes did try to get through to bullies. What it comes down to is kids were cruel and they knew it was wrong but they got off on bullying anyways. It was always contagious so if one or two bullied a person, the entire class would join in.
I wonder if the anti bullying campaigns today are making any difference in schools. Just to clear up how cruel and sick teens have become... I remember the teacher talking to us about bullying and students were saying things like if they are too weak to stand up for themselves they deserve it, if they kill themselves they deserved to die.
I can even remember us watching a video about 911 and my class was laughing at it saying they were glad the planes crashed and who cares about those people since they didn't know any of them. This is how sick kids today have become for anybody that wasn't aware of it.