The problems of DRM are the ones facing us right now. Sure, individual implementations are buggy. If there's pressure, that'll improve over time.

The basic technical approach of the current DRM systems is sound, which is why they're a problem. High quality implementations would restrict people.

In terms of pattern recognition, you're not exactly doing facial recognitiion. The hard part would be putting a signal in there which was:

- distributed through the whole picture (so you can't just mask off the logo in the corner)

- sufficiently unobvious to humans threshold so that quality doesn't go down too far. Dunno about this one, apart from the fact that we have a lot of bandwidth here to hide a signal

- could survive basic disruption attempts by 'hackers' (colour filters etc)

It is a fairly tall order, but so is convincing the entire PC parts industry to put crypto in all their components against the interests of their customers.