I believe that in some countries exist such laws. I'm not sure, I don't remember exactly but I believe, that here in estonia one person who not feed own horses was banned owning animals. (brrr... englis is so hard) I don't but almost never my dog to lead. I just have a bazooka. And if my dog ton't kill dangerous beoples who vant sue me, because I don't but my dog to lead, or because my dog barking. Then I kill self those persons before thei can sue me.
Actually I think: Must teach peoples allreadyk in kindregarten, how to act with anymals and owning anymals. There is not needed laws, like that u must keep your dog on leads or muzzled. here in my hometown is this law. I think It's owners responsiblyti. If owner feels tha't he/she can trust his dog, then it's not my business, at least so far when nobody don't atack me. And even when dog atack, then its not always dogs or owners fault. some beoples is just so stupid. Really peoples must learn how to act with dangerous dogs.