Things They Should Study: bullies who tell their victims they should kill themselves

Today's Annie's Mailbox has a girl whose bully is leaving her MySpace messages saying "Why don't you just go and kill yourself already?"

I've heard of this bullying method before, although it was never done to me, and I really think someone should research it. We could use more information about the perps motives and what they're thinking, because this makes even less sense than most other bullying techniques.

My bullies bullied me when we were unwillingly all in the same place - at school or on the bus mostly. But in this technique, the bullies go out of their way contact the victim at home outside of school hours. If they really think the victim is so worthless they should commit suicide, why would they go out of their way to contact her during free time that isn't being marred by her presence?

Also, I don't know if this is broadly applicable, but within my own circle the victims who were being told to suicide were far cooler than me. (To me they looked like they were on par with their bullies in terms of coolness, but they were all several levels above me so it's possible I couldn't see the distinction.) In callously cold and objective terms, I was a far better candidate for suicide than these victims, but no one ever suggested that I should commit suicide. And now that I think about it, those particular bullies were never cruel to me. We certainly weren't friends and some of us didn't quite get along in a sort of cold and distant and avoiding each other way, but they never actually bullied me. Why would they do something so much more drastic to the cooler victim while leaving the uncool victim alone?

I'd love for someone to seek out adults who used to bully this way and find out about their motivations and how they chose their victims. Even moreso than regular bullying, it's a giant mystery to me.