I agree with Val. Service dogs are working dogs, and obviously are out to do their jobs. Every time I've met one in public, their human asked politely for me not to talk to the dog, pet him/her, etc. You can tell a working dog from the average pet dog. And if people start putting the fake vests on their dogs, then stores and such will be leery when a real one comes in.

I'd rather see a change in public attitude towards pets in public instead of trying to fool the public into thinking my beloved pet dog was a service dog.