That would be fantastic - I'd love a system that would stop someone taking more photos if they already had too many similar pictures in their own camera roll. Just think of the time it would save when someone is boring you with their 1000s of holiday snaps :)
Thats addressing the problem at the wrong end. I take many photos of the same subject often, but Im only ever going to show the best one or two to anyone. People need to learn to edit! There is a side benefit that you look like a much better photographer when people only see your best. They dont even think about all the rejects.
