What ever happened to "If you can't say something nice, don't say anything at all" approach? That is something people should take to heart today. So before you write a comment about how unattractive someone is or what an idiot someone is, maybe you should put yourself in that spot and dig deep in your empathy basket to see if you would appreciate those comments directed at you.
It seems also to be the same old bullying techniques that have been going on for years, only they are public and more humiliating to the target. Does it make that person feel better to put someone else down online. It should make them feel worse.
The world is small and tolerance and understanding is what builds friendships. If you're sitting home alone, bullying other people online.... you need a friend. Someone that will love you for all your positive parts and overlook your faults, not advertise them online.
The basic for treatment... treat others as you would want others to treat you. If you are unable to put yourself in someone else's shoes and empathize with their situation, maybe you should keep your comments to yourself.