Pit bulls in my small town love seem to love me whenever they break out (which seems far to often for my tastes), freaking Yorkies however... nibblin' bastards.
Pit bulls need responsible owners, and are often used as status dogs for the "oh so tough guy" and are abused. As for dogs in general responsibility is key, you need to teach them or they are gonna do what they do by default depending on their breed. They are what you make of them.