Doctorow is gesturing at something significant, but he's still stuck in the '90s era copyright wars. I agree that the DMCA is awful, but it's irrelevant to the problem.
Today's tech corps don't need to sic the cops on you if you use their products outside their prescribed boundaries. They can just ban you, and that's punishment enough. We're already hearing Kafkaesque stories of people accidentally tripping automated abuse-detection and getting locked out of their GooFaceTwit accounts with no recourse. If you're considering actually violating the TOS... well who'd want to risk that? Better to just stay in line like a good little drone.