Interestingly, the iTunes store does (or did at the time of PyMusique) this too, even though they don’t use P2P.

I think what Bram meant by “user interface” (although I obviously can’t say for sure) is just the overall appeal — or lack of appeal — that such a service with DRM is likely to have for users, as opposed to the technical UI design.

I would agree with your central point though. In effect, DRM is trying to change the way that people have thought about content for decades, and that is darn near impossible — or at the very least pretty stupid.

I think that Cohen’s phrasing of it as “user interface implications” trivializes the real problem. It sounds like marketing spin, suggesting that the problem could be fixed with a lil’ spit n polish to pretty-up the user interface.

That’s wrong: the “implications” of BT’s DRM’d system run very deep. People hate these systems not because the UI is a little ugly–otherwise no one would have put up with years of hideous open-source BT clients–but because we feel these restrictions emotionally: What do you mean I don’t *own* it? Why can’t I share it with friends? Why can’t I move it to my Mac and then to my iPod?

Those aren’t just some missing features, those are the basic personal and social behaviors and expectations around buying and using media products.