> You enforce the restriction by prosecuting people who upload the footage.

but this is impossible to guarantee as well

It's turtles all the way down. If we had a way to perfectly prevent people from doing undesirable things, we wouldn't need courthouses to begin with. The system doesn't need to be perfect, it just needs to be good enough that reliably circumventing it isn't worth the effort.

It sure changes the incentives though. It’s much less attractive to leak recordings as a PR move—or realize any benefit that cranky humorless judges can trace back to the recording—if that, in and of itself, constitutes a whole new crime (and effectively confessing to it too).