people following you and yelling are wrong. it is not their place to judge your disability. if someone thinks you are scamming, maybe a chat with the manager of the store would be appropriate. then the manager could question you reasonably IF THE person feels they need to take it that far.
people are nosy, pain in the butts that at some point must mind their own business. MANY disabilities are NOT noticable that could be claimed as full disability.
my friend has a stroke at 43. Then a few mini strokes after. she now only walks a bit off and her stride is a bit different. You wouldn't think she was permanently disabled unless you talked to her. she has trouble speaking well so if confronted, and UNLESS she speaks, you can't tell she is in a mess of medical troubles! If I was with her and someone came screaming in her face, I would probably deck them ! :) ;0
You don't need to tell anyone your business! I wish people would grow up literally. Sure there is abuse of permits (on all things in this life) but should a person attack a person when they don't know the real circumstances, just cause they know some abuse is out there on these permits. My answer is a huge NO!