The problem I see with breed-specific bans is that they're doomed to failure.
Gangsters will always want a "fightin' dog".
There are many dog breeds with powerful jaws and a tendency to be territorial.
It's not that hard to breed and train dogs for aggressiveness, especially if you're an unscrupulous breeder or trainer who doesn't care if their dogs are controllable or if they die in the process.
So: some other breed becomes the new gangster "fightin' dog". Like that Thai Ridgeback, for example. And the whole cycle starts again.
Here's the same situation, with cars:
-The car most often caught "street racing" is a riced-out Mitsubishi Eclipse.
-Therefore we will ban the Eclipse. Problem solved, right?
-Wrong. Kids will just rice out another car and race that. There are a lot of different cars in the USA.