I moved from a bigger city to a smaller town around 4-6th grade and got bullied. Not very badly in a straight way but more like clearly ostracized. I think I carry some scared wounds from it also nowdays, even of course I've grown a lot during all these years and got the most of my confidence towards people back. About cyberbullying, it's something I've luckily never experienced.
If my memory serves me, the Jokela school shooter
(the school shooting which happened here back in 2008 ) was heavily bullied. Then he started to seclude himself mentally from other, normal people and create his genocide plans and ended up a massacre.
I think it's a lot because of immaturity. Children and many teens can't step in someone else's shoes and like most of adults can do (even seems that some adults will never reach that empathy stage either) and many things seem to be pretty black-and-white before these youngsters start to find more tones when growing up. Besides that it's easy to find some outer target in which to project all these negative feelings when you're feeling unsure yourself and about it who YOU are. Some of these teen harassers will be all wise adults when they once grow up. I'd say that happened with most of those teens who ostracized me too.
My opinion is that school and parents should be interfere in things IMMEDIATELY when somebody starts to bully someone. Also social workers and even police if the situation needs it. I think we would need more preventive work too. These children, teens (and some adults) need to understand that the victim of bullying is a human creature with all these feelings too.
Crimsonhorse, some people are just more sensitive than others, especially during their youth times. Even I recommend that ignoring thing too as a first step since it has effects on some teasers, I can believe that when some person or people just bugs and bugs you, you finally just can't ignore it anymore.
ETA: This thread had gained many news answers during I wrote mine so I could add: It's not words all the time. How you can ignore it when the teaser, after noticing that words will not hurt you, starts to threaten you physically or just does something else in practice. I've luckily never been there personally but sometimes felt it would have been turned like that soon and know some teasers go there.