Bill Thompson blogs on why DRM is a bad idea. Not surprising since Bill has been one of the champion in restricting the proliferation of (bad) DRM schemes.
I wrote an article a couple months back on the issue of DRM but since then its been sitting on my harddrive outdating itself away while I whittle on with my life. Hopefully I would be able to publish it soon. It has a slight anti-iPod overtone to it but overall its more about MP3's inadequacy and DRM's failings.