On Facebook it is very easy for cyber bullies to thrive. They can harass and/or gang up on one person even easier than they could in a school environment. There aren't moderators that go around monitoring what people say to each other. Anything can be said. There are also a relatively small amount of parents that have Facebook accounts and keep up with their children's. More than once I've witnessed this form of bullying, whether it be about race, appearance, intelligence, etc.