It's a shake down, but I haven't figured out how to protest it. I register my dogs, but that's mostly because I don't want to run the risk of trouble if they make a break and go running through the neighborhood. If my dogs do get out, Fulton Co isn't getting the call. A quick look at the collar shows our name, and the vet's office. If the collar was missing, they'd have their microchips scanned, and that's where I worry about what animal control might do if Peter & Clifford aren't official.
Good pet people are going to take care of the rabies shots, whether or not they register. Bad pet owners aren't going to take care of the shots, and those are also the people who wouldn't bother to send in the registration form. It's not a good system.