Re: the problem with DRM systems
That's why I made the point about if you were worried about quality. If the movie is still only in the cinemas then yes, cams and screeners are all you can hope for. But once the DVD or BD comes out - it's fair game.
Suppose your playback device (say a PC or set-top box) keeps the video signal encrypted even through the monitor cable, and so the monitor itself has a revokable key to decrypt the signal. At some point between the encrypted video-in port and the screen, the signal has to be decrypted so it can be displayed. A competent cracker can open up the monitor and patch in an intercept circuit that captures this unencrypted signal as it's hitting the screen. This captures the video in the original quality.
Likewise, even if the audio going to a loudspeaker is encrypted and the speaker box itself has to have a key, at some point inside that box, the signal gets decrypted so it can actuate the coil that drives the speaker cone. A cracker can capture that signal, again in its original quality, and combine it with the video to create a near-perfect copy of the original. There may be some loss depending on how he does it, but using these methods it's perfectly feasible to produce a high-quality HD copy that's visually and aurally indistinguishable from the original. And this holds true regardless of the depth and sophistication of the DRM system used.
And it is also true that this requires some technical knowhow, and so may be seen as being beyond the means of the average Joe to achieve. This is the stated object of modern DRM - to make it difficult rather than impossible to copy. But this is where Bob being Mallory comes in; the encryption only needs to broken once. As Mallory, Bob has cracked the message and can now distribute it - via bittorrent, bitlockers, USB sticks, or the P2P system du jour, whereby the average Joe can easily get a high-quality, unprotected copy. And the more the DRM imposes limitations on what Joe can do with the file, the more he will continue going to P2P to get himself a DRM-free copy - even if he's done the right thing and bought a restricted original.