I have some personal statistics for just such occasions:
I figured out that by last count, in my career I have trained twelve pits and pit mixes. I have also trained twelve Yorkshire terriers. These are clients who either went through my entire basic obedience course or my problem solving program. I have never been bitten by a pit or pit mix. Four of those twelve Yorkies bit me. Understand that I work with dogs every day, so by necessity I'm an expert at diffusing a dangerous situation before it actually escalates into a bite. I have no doubt that one of those pits could've caused more damage in one shot than all those Yorkies did, but the point is that they didn't. I don't even recall ever feeling threatened by one.
In fact, there have only ever been two dogs in my entire life who actually frightened me. One was a greyhound who'd been constantly abused by his race trainer and left to die in a ditch with a broken leg. (His new name is "Lucky" and we're best of friends now. He scared the pants off me when we were taking him out of his kennel at the rescue. He didn't bite, but he made it clear that he fully intended to at the time.) The second was a Rhodesian ridgeback with too many testicles and too little training. He thought it was hilarious to scare people. It worked on me the first time, until I figured out what he was doing.
The point is, dogs aren't monsters. Even more, particular breeds aren't monsterous. Statistically, pits aren't any more likely to bite than labs. Making generalizations about breeds is cruel and dangerous and is the cause of a lot of pain and death. It's racism, and it should be just as taboo as racism between humans.