This is a low priority, highly abstract hardware idea.
Instead of taking screenshots people sometimes take a photo of the phone screen itself with another device equipped with a camera. Now this is not preventable at the app level or even at the software level. This is more of a hardware phone level problem. So one possible solution to this could be to use some kind of privacy screen (something along the lines of Thinkpad privacy screen) that would distort the images taken of the screen.
This is a low priority, highly abstract hardware idea.
Instead of taking screenshots people sometimes take a photo of the phone screen itself with another device equipped with a camera. Now this is not preventable at the app level or even at the software level. This is more of a hardware phone level problem. So one possible solution to this could be to use some kind of privacy screen (something along the lines of Thinkpad privacy screen) that would distort the images taken of the screen.