I'm generally against regulating this type of thing (ownership of pit bull terriers) and I won't go against it here. However, I'm entitled to my opinion and my opinion is that they are apparently VERY dangerous to the surrounding public.
Therefore, in my opinion, if you are going to be an owner of such a beast, you are on notice from day one, that you own a potentially deadly animal and you will be held strictly liable for its actions. Since this is not usually the law, with some notable exceptions, I choose for it to be my law.
Therefore, all you pit bull owners are on notice, if your pit bull attacks anything I care about, I will shoot it dead, period. If I don't have a gun at the time, I will hunt it down and kill it. If you, as the owner of said pit, have a problem with that, I will do everything I can to enable me to do the same to you without imposing liability on myself. Because as many pit fans on this thread have stated, the fact that the pit attacked is really due to how you raised it.