While many incidents are directly the fault of the dog owner, many more are the indirect fault of the dog owner for owning a dog which was bred for a far different context than the conditions in which the owner lives.
...sometime, in your spare television watching time, turn to the National Geographic Channel's "The Dog Whisperer" and get back with me. While I agree that the American Staffordshire Terrier, Staffordshire Terrier, American Bulldog, Dogo Argentine and Bull Terrier all have roots back to the "pit," they all can be socialized to behave properly--just as Doberman Pinchers, Rottweilers or German Shepherd dogs used in police work will not attack unless ordered by their handler to attack.
Check out the National Geographic Channel Monday at 9 p.m. Eastern...Ceasar has a kennel full of "pitbulls" and all of them are non-hostile--again, proving the breed is not the problem