When Should BYB'ing go from Unethical to Illegal?

That isn't what I consider a BYB - they are a puppy mill. There are several states & more considering laws which does limit the number of breeding dogs & litters produced yearly to help control/remove mill operations. Sadly where they are located mostly in areas doesn't have any laws like that & being more rural & Midwest area has a few laws protecting pets. My state has a law where anyone selling more than 2 litters a year must be registered thru state but that law is largely ignored or unknown by population. It just makes me sad & disappointed in humans.