As soon as someone raises his or her hand and makes it clear they don't want to be photographed, I stop right there.
If someone shoves a camera in my face, I think my reaction would be to grab the hard metal/plastic object and either shove it away from
my face, or pull it toward me.
There was a woman in Little Rock who was doing this sort of thing, and I followed her for a while, taking many photos of her at work.
She got offended and told me to shove off... in far ruder words. I grinned and kept snapping until she left in a huff.
I wouldn't go passing laws or using other types of force to tell folks how to behave, but don't be surprised if a rude photographer gets a little of
her own medicine from time to time.