While pit bulls have not attacked me yet, I have been around them and sitting in the same truck with them can give one an idea of their enormous power.
Finding their favorite breed under attack by the media, many Pit Bull owners have responded by irrationally downplaying the Pit Bull breeds tendency towards violence and their capability for violence.
I have a Bull Mastiff. She is both more likely to attack than a non aggressive breed, as she was bred for the FUNCTION of being an aggressive guard dog - and more likely to cause extreme damage once engaged in violence. Because I recognize these two facts, and keep them foremost in my mind, the possibility of her actually attacking anyone and/or their dog goes way down.
Now if I wanted to try to claim that Bull Mastiff's don't bite (they usually tackle), that my Bull Mastiff wasn't any more likely to attack than a Labrador, or that the result of her aggressive behavior wasn't any more of a concern than the aggression of a Labrador..... the likelihood of her getting herself (and me) in trouble just increased EXPONENTIALLY.