Remember, most of them are cowards who's full of talk. One of the most common reason why people do cyber bullying in the first place is because they have full anonymity with very little ways to get caught. So they know that no one will do anything to them. Also, usually the people who does it is either a bunch of little kids who doesn't have anything else to do but to be rude towards people online and a bunch of immature adults who never quite grew up and needs to fill an empty void in their hearts by beating people up online without having anything fighting back at them.