[Mr Ramsbotham]

Owners of breeds such as this, that are known to be aggressive and have the potential to do much harm, ought to be made to post a bond for their good behavior. No bond, no license. It wouldn’t prevent all incidents, but it would go a long way toward reducing them, and would have the salutary effect of discouraging irresponsible people from owning such breeds.

[Cronos]

I think it's true of all breeds. Around where I live there are lots of German shepherds. Many are unruly and attack smaller dogs. But I know one that is exceptionally well trained and he will NOT attack another dog. Needless to say the owner keeps him on a leash all the time except when he is closely watching him

People who own dogs should know that this is a responsibility, not a toy.