There are a couple of pit bull adolescents in our dog park. They love to grab the plastic "chucker" I use to throw tennis balls. It can be unnerving because they are VERY STRONG and they DO NOT LET UP.

Unless I'm dealing with a reputable breeder of American Staff. Terriers that can show me an AKC lineage, I would not own a dog of that ilk. If I'm dealing with a backyard breeder, I don't know what's in the woodpile in terms of temperament. These dogs are STRONG, both in jaw strength and in body. I think I'm a pretty good judge of dog character (obviously I need work in the human component - especially friends who wants dogs...grrrr...) but frankly, I don't want to be constantly vigilant around my dog. I had one German Shepherd who was dog aggressive - never again (it was my own stupid fault though for not socializing a puppy that desperately needed it.)