Why are the vast majority of dog-bite fatalities caused by pit bulls?
http://en.wikipedia.org/wiki/List_of..._United_States
This is what you call prima facie evidence that pit bulls are dangerous.
The pit bull lovers refuse to acknowledge this, but the fact is that pit bulls are dangerous because they have such a powerful bite. All it takes it one second in the lifetime of the dog for a tragedy to occur.
A few years ago I had a Yorkie who was the most gentle dog in the world. One day we were playing, and the most gentle dog in the world suddenly bit me on the hand. He immediately realized what he had done, looked me in the eye with the most human look I've ever seen on a dog, and then he ran like hell. His bite didn't even break the skin. If that Yorkie had been a pit bull, I'd have pulled back a bloody stump. And instead of running away, he may very well have decided to just finish me off, because pit bulls are known to do that and have the strength to do that. If my Yorkie had tried to finish me off, I'd have picked him and thrown him against the wall.
Some animals are just too dangerous to have in a home, especially a home with children or in a neighborhood with children. I don't give a shit about the anecdotal evidence people provide about their personal pit bulls who were perfect little angels and the bestest dogs ever. 99% of them may be, but the 1% who are killers make the breed too dangerous to have as pets. It's trivially easy to find reports of children killed by the family pit bull. Invariably the parents are hysterically sobbing "But he was the most gentle animal ever! He never bit anyone ever ever before!"
Banning pit bulls is nothing like banning guns. An unattended gun won't escape from its pen or jump a fence and kill people. Pit Bulls can and do.
Hog Farmer nailed it when he said "Guns don't kill people. Pit bulls do.".