Cyberbullying is a form of bullying which involves using the on-line resources. It is a lot more popular and widespread because of the relatively high degree of anonymity most websites provide.
Cyberbullying a form of trolling, as it also tries to harm someone or drive someone mad for someone else's laughs. Unlike other forms of trolling, it is usually directed against a certain person (as opposed to a group of people). This often means the perpetrator is someone closely connected to the victim: for example, a school classmate, a relative or a former boyfriend/girlfriend.
In the last few years, the Conservative media tried to use cyberbullying as a scapegoat to demonize the Internet as a whole (again). (Why do Conservatives hate the Internet so much? New ideas spread through the Internet which makes it harder for Conservatives to hold onto their traditions. New ideas spreading through the Internet make it harder for Conservatives to get other people to stay traditional. Naturally Conservatives look for any excuse they can to denigrate the internet.)