I agree with standing up for yourself to a point. I use a wheelchair or scooter but can walk a little bit.
I went into home depot, as you know very large place. in THIS home depot they keep the scooter right next to the return desk. There was a line for the return desk which started about ten feet back from the actual desk, I preceded to head for the scooter, which has nothing to do with waiting in line to get, and this man, said Lady get the F to the back of the line.
I was so flabergasted I couldn't speak. I set off on foot to find my husband and almost collapsed.
Moral is be sure someone is trampling on your rights before you take them to task.