A worrying story from the BBC website suggests that the problem of cyberbullying has taken a new twist with teachers now also becoming victims.
As a relatively new phenomenon, there currently appears to be little available research in this area; to date, cyberbullying research has focused on cases where children are the victims. In July last year the Anti-Bullying Alliance published An Investigation Into Cyberbullying, which is possibly the first major UK study to look in detail at the problem.
In response the DfES has issued a set of guidelines to help schools, parents and pupils prevent and tackle cyberbullying. A free information sheet with similar tips is also available from the Anti-Bullying Network, while if you're completely new to the subject then Becta's article What is Online Bullying? should bring you quickly up to speed.