poorly behaved “service dog” trained for personal protection

United States.

Friend of a friend previously had a service dog. I don’t think he should have been allowed to do public access because he was reactive (barking, snapping) to dogs and sometimes people, so I already don’t love how she handles her dogs, but whatever.

She got a new dog recently that she wants to make a service animal. It’s an off-breed and she plans on owner-training with no professional help. Her idea of training, as far as I can tell, consists of shouting “no sir” and stomping her feet, repeating commands 10-15 times with no response until she physically moves the dog into what she wants it to do, and not much else. The dog has been way over threshold every time I’ve seen it, it’s almost guaranteed to wash, but I’m pretty sure she won’t accept that and will insist on public access anyway as long as it can do her medical alert.

She also wants it to be trained to protect her “just in case” and also “protect itself from other dogs” which sounds like just a matter of time before someone is hurt and/or killed.

Are there any laws/anything I can quote besides “don’t do that” to convince her it’s a terrible idea? Service animals really aren’t regulated at all in the US as far as I can tell, do I just have to wait until this dog bites someone and hope it’s not too severe, and until then she’s allowed to take it in public and dog-free spaces as a service animal? She’s developmentally disabled too and doesn’t seem to understand that she can’t just do whatever she wants as long as it’s not expressly illegal, but this dog is going to be dangerous when it grows up. Anything I can do?