From experience and experiences I've heard from numerous people (as a previous mentor), trolls and cyber bullies do tend to will target those who seem vulnerable. Sad world we live in but unfortunately true. They will target the young people (and in older people to) those who they think and probably know that their comments will bother them; that is after all what they're looking for.
So where am I going with this?
Always being someone who was taught to be realistic, bullying can only come to a minimal point.
If we could (and we and others do try) encourage self-esteem and raise confidence in the victims the bullies would get bored, right? In theory. I mean no bully goes for the person who looks strong in them selves, who just wipe of comments like they're nothing.
No way am I saying this is an easy answer, the same as wiping bullying is never going to be easy. But if young people can be supported and worked with on a personal level to enhance their self-esteem, given the chance to learn they are not what they're told, they are human, they are strong, that they deserve to be treated with respect, then that person is going to be become less of a target.