This is a great essay:
Science Fiction, Copyright, Natural Law, and You, by Science Fiction Writer and OpenCola founder Cory Doctorow, that brings up a lot of issues surrounding copyright that most writers have probably been trying not to think about.

Bottom Line: Digital Rights Management doesn’t work, and that means once a digital copy of something exists, it’s “out there”, and it’s going to be replicated. And any encryption protections are ultimately compromised. What does all this really mean and what can really be done about it? Cory attempts to get a discussion going by helping us read the writing on the wall.