I read a great article in the NY Times about Trolls. Internet Trolls. People who basically get in the way of people who try to use the Internet for a useful purpose. The people interviewed sounded like sociopaths. I understand why this is.
If you are in a room with a real human being and you walk up to them an insult them, their family, or try to steel their wallet, you have to suffer instant physical, social, and emotional consequences.
On the net you can do this with the barrier of electrons between you and your victim. Troll are pretentious cowards. They seldom are held to account for their actions. So the cowards continue hurting people. At some point the mess they make will end up in their midst. Behind bars, in the drunk tank, in a moldy blanket under a bridge, struggling to eat, they will finally face the consequences for their behavior.
If you act like a jerk, be prepared for people to treat you like one.