There are some very narrow minded views in this thread.
Its not the dogs that are the problem, its the owners. Every dog has teeth and could do serious damage just that some are seen as status dogs and used as weapons.
I have a dobermann and despite its appearance its the softest dog you could meet.
Also, ive never met a nasty staffy yet. The only 4 dogs have had a nip at me, 2 jack russells, 1 westie and a springer spaniel.