I've raised an AMISTAFF, or American Staffordshire Terrier for 9 years and she is loyal, fierce and courageous, has never attacked anyone, but she protects me. This breed is beautiful. There is also a breed called bull terrier, evolved by slang usage to be 'pit bull'.
Ignorance has attacked this breed as well, fear and ignorance, misuse of training and breeding. Dogs have instincts and some do attack humans. This is no valid reason to generalize the characteristics of the breed and turn it into a prejudice, stupid prejudice that's it. This breed is the only dog I will ever have, and I would rescue some if I had the land space.