Breed as distinct from type ? Fila Brasileiro. Any breed which has a rule that the judges at shows are not to touch show dogs is a dangerous animal ! It was bred as the ultimate guard dog for plantations and has an inbred hatred of strangers (hence the judging rule). It's also massive, with jaws to match. The breed is so dangerous that it listed in the Dangerous Dogs Act.
German Shepherd Dogs are sweet, friendly little things . AAAAH ! Seriously, they are very intelligent, easily trained and controlled. Accordingly, they make good police dogs. They shouldn't bite save on command. A 'bad one' is like any bad dog, not properly socialised. In contrast, the Fila has been bred NOT to be socialised, and isn't whether the owner wants that or not.