There are nasty people who buy Pitbulls and abuse them, consequently if I see anyone with a Pitbull I am concerned.
I live in the UK and a lot of rough lads buy Pitbulls, they want their dogs to be aggressive and abuse them to make them aggressive.. Because of this the kind and considerate dog owners who have friendly dogs, get tarred with the same brush.
Pitbulls are banned in the UK, however I suspect that they are still available and are sold to the wrong people who do not make any effort to understand them. They are used as weapons. Because they are banned in several countries, this does not enhance their reputation, consequently they will always be maligned.
I adore German Shepherds and I have shared my house with several extremely friendly dogs. My dog was mauled when she was on her lead by a German Shepherd, she failed to defend herself and when I got stuck in, I too was injured. Now I am concerned about GSD's and I would run a mile if a Pitbull approached my dog or an out of control GSD.
I have read that caring breeders are now docking the tails of Pitbulls, apparently this discourages idiots from buying them to fight. I am told that fighting dogs are separated when their owners grab the by their tails and without tails they will not be bought as fighting dogs.