Aye, cyber bullies are a big problem. I haven't been cyber bullied personally, but I'm sure I've encountered them. I usually see people pick on a member and then back off after a bit. That's just as shameful, in my opinion. However, I haven't really seen those cyber bullies who thrive on tormenting people to the point of harassment and personal devastation.
I guess I see more cyber assholes than anything. They act arrogantly, criticize people unreasonably, pride themselves on their own intolerance, and have very little remorse for doing so. No one likes them, other than those who share their world views and those who aren't their target, and absolutely no one respects 'em. You'll find these people everywhere. They all have a similar air about them: in-jokes, arrogance, intolerance, ignorance, disrespect, etc. The difference between these blokes and cyber bullies, is that these assholes don't get a sick joy out of tormenting people, it's just that they do it for no apparent reason.