The only thing I would add is that we often work with the bullies as well as those being bullied. Although there isn't a traditional profile of any kind, often these are kids who have had just a tough time, who haven't built up the confidence. It often stems from a lack of confidence, and it's a way to gain respect. It's many of the same patterns that lead young people to join gangs. It's a way to gain respect, it's a way to feel some strength, to feel some power.
So we work a lot with kids who we've identified as having some bullying...who themselves are being the bullies. We work with them to look at what's creating those behaviours and how to put that in reverse, if you wish.