It might disgust you, but it is human and child nature and therefore that is how it is and isn't going to change now, or ever. Turn your facebook off, ignore people, or better yet, hope you are born with parents that teach you these things so that you can stand up for yourself.
bullying is part of social growth in younger humans, that is why it has been here thousands of years and is just as strong now with no sign of slowing even with all these anti bullying movies/campaings going on. It is part of learning social structure, dominance, confidence, the ability to stand up for yourself, and many other things.
Fault new-aged pussificated parents for not raising their kids to be tough enough to handle it or stand up for themselves, not a child's natural behavior.
Bullying is a part of social growth for the bully and stunts it for victims. Fault the parents for not raising there kids to be tough enough, how the hell are they supposed to raise a kid who is undersized to be bigger or stronger?