I will never understand why people have pit bulls. Especially people with children. I have Labrador Retrievers and they never are aggressive.
Yours might not be, but the only dog that ever bit me was a Lab. I was 11 or 12, riding my bicycle up the street, and the dog came out of its yard and got me on the hip, barely breaking the skin. My dad talked to the owner and the dog wasn't allowed loose after that. Those were the days when everybody didn't sue everybody else over everything.