any dog can bite. any dog can be aggressive.

pit bulls were never called "nanny dogs" no dog breed goes from bull baiting and fighting to babysitting children as a breed tendency.

just as there are very nice pit bulls, there are some very aggressive uncontrollable ones out there. if a dog with a questionable background is not trained, neutered, and watched you are asking for trouble and placing others at risk.

it's jaws are powerful..they were designed for a purpose. just as other dogs have features designed for what they were bred for, that is what pits functions were.

again, from a good breeder, raised responsibly, trained, i'm sure the dog will be a better less risky pet, but still as with any dog, you need to watch them in situations that put others at risk.

much depends on the owner's behavior as well...everything being said, it is not a breed I would have (but there are plenty of other breeds on that list as well)