I think there should defeintly be a defining line to this law, which often they fall short on!

There is a clear and obvious difference between breeding and selling dogs from your home, and just happening to be a foster mom/dad who saved a litter of puppies, and gaining money to reinforce the fee's of all the other animals you have to spay/neuter and other such vet bills.
Besides most people who are fostering don't always just happen to have litters of puppies around for adoption, like people out there trying to repeatedly breed and sell dogs for a buck.