"Cheaters" yes, constantly.   From fast food places, to supermarkets, to Walmart...even a recent experience at JC Penney.   A small dog on a  leash in women's clothing that I almost tripped over.   If I spot one that isn't a service dog, I complain to a manager immediately.  They always react the same way...with a shrug, with 'it depends', etc.   Many places are too lax or turn a blind eye.  I assume they don't want to deal with repercussions, but with that they set the wrong precedent,  imo.