Yeah, but let's be honest, if I had a job as a manager at a theater and a moderate amount of reverse engineering skill or a small team of friends with those, well, time, access and tools combine quite well...
Sure, they make it look all secure, pass it through all that crypto and stuff but ultimately it has to be passed to the projector chip in some form which is unencumbered to be turned into light. At which point it's fairly trivial to dump. Anti-tampers on the case are probably fairly limited.
According to another comment here, the anti tamper mechanics on those projecters are not limited. They are in fact quite aggressive.
If they have been any kind of smart when designing them, the decoded stream takes a limited, shielded, and highly tamper resistant path to the projector chip, and each and every critical component are paired with each other such that switching one of the out automatically destroy all keys.
I'm under the impression that the last level of decryption is done in the projector chip itself. So while accessing the unencumbered stream is theoretically possible, it definitely requires a lot more than a moderate amount of reverse engineering skill and serious amounts of equipment.
Sure, they make it look all secure, pass it through all that crypto and stuff but ultimately it has to be passed to the projector chip in some form which is unencumbered to be turned into light. At which point it's fairly trivial to dump. Anti-tampers on the case are probably fairly limited.