I've seen this in person. You cannot imagine the damage being done to these tiny defenseless animals. They're kept in cages barely large enough for them to turn around. Usually the cages have wire bottoms, which are horrible for any animal to stand on at length or worse, lie on. Most of these puppies never even feel ground underneath their paws until they are purchased. Worse yet are the females they keep for breeding. They NEVER get out of the cages and are kept pregnant until they are considered no longer viable as producers.
The only thing that can stop this is the legislation and more importantly, the enforcement of said legislation. Your signature WILL make a difference and better still, share it with your friends.