Persistent marks as copy protection doesn't work for media mainly because they deal with the consumption rather than copying side, so just one single non-compli

Persistent marks as copy protection doesn't work for media mainly because they deal with the consumption rather than copying side, so just one single non-compliant legacy device spoils the entire thing. As for fingerprinting, that's a whole 'nother can of worms. I've never seen it be used for DRM specifically but it has been successfully used many times to track down who was leaking trade secrets etc. In fact it might be more widely deployed than most people realize. The problem with fingerprinting for DRM would be the plausible deniability of an unsuspecting user "getting hacked" and then their fingerprinted copy ending up as the illegally distributed one without their knowledge or control.