You’re joking, but yes, that’s actually a thing.

Watermarks with detection in cameras and scanners, be it the simple EURion constellation[1], ContentArmor[2] or the watermarking techniques developed by Denuvo, these things exist.

Some directly prevent you from photographing the content or filming it, others tell the camera to add identifying information steganographically. Even others are only used for ContentID. All of them work even if the material is going through analog copying.

[1] https://en.wikipedia.org/wiki/EURion_constellation [2] http://contentarmor.net/