> Neither does anyone else. And if you're a mathematician, then you can PROVE that nobody does know how to implement DRM.
That's not as interesting an argument as it sounds like. If you're a mathematician, then you can PROVE that nobody knows how to do static analysis (since it reduces to the halting problem), but people clearly do and it's clearly useful on real-world code. Nobody knows if SAT is in P, but we have SAT solvers that operate in bounded time on any real-world problem thrown at them, etc.
DRM is about making it harder to exfiltrate content than to acquire it through the intended means. It doesn't have to make it impossible to be successful. I pay for, e.g., Rdio, which uses DRM to prevent me from walking off with their entire catalog. I can do whatever I actually care to do within their restrictions, and continue paying, and clearly so do lots of others. So it's a pretty successful DRM scheme, even if it's theoretically unsound.