Ok, I just listened to Doctorow's piece.
By the way, the link to the audio file is wrong, it's
here
Harryt, have you listened/read it? It's nothing to do with Doctorow's views on copyright. What he states here is simply what any half-competent mathematician/cryptographer will tell you: Fundamentally DRM can't work!
That's why DCMA and the like exist. If DRM could work, governments wouldn't have been lobbied into passing such laws.