In the UK, American Pit Bull Terriers (and three other breeds) are banned. Dog bites have increased significantly since the implementation of the law.
Here's a recent case of the sad realities of BSL. There is a young man who permits his bull mastiff to run loose. This dog is very dog aggressive. He attacks an "illegal" pit bull being walked by his owner - rips open the dog's throat. Guess what? Pit bull is deemed illegal by the Department of Agriculture. Fascinating.
Bull Mastiff has now attacked another dog tethered outside of a pharmacy (a good reason not to leave your dog unattended while you shop).
Now authorities are heck-bent on finding this bull mastiff's owner! First, though, they have to waste money on prosecuting a citizen who had the audacity to walk a "pit bull" on leash. Then maybe they'll find the owner of the highly dog aggressive and dangerous bull mastiff.
BSL: Hardly Working!