The Picker MobBlog about the failure of the DMCA to impact the "darknet" -- that is, to achieve its ostensible aim -- has officially ended, but it only takes one smart respondent to wander past the gates. Check out where Wendy Gordon arrives today:

[Both Fred von Lohmann's] paper and this blog have been concerned with the next question to arise: once we assess the (in)efficacy of the DMCA in doing what it was supposed to do, what are the costs to be weighed against the alleged benefit? ...

To pull this all together: What we've been calling the "retail" level is really the level of the lawful user. As several posters have pointed out, the DMCA doesn't stop unlawful copying by those people -- they'd obey the law anyway. For them, what the DMCA does is stop fair uses, and impose extra costs (and contracts) on the use of material that might otherwise be lawfully and freely available. So the DMCA can be seen as a law that hurts the lawful users, to stop the unlawful ones.

In turn, that reminds us of why the question Fred raises is so important: for what purported benefit does the DMCA sacrifice the lawful use of information?

Update: You might also enjoy some Picker MobBlog metablogging by Derek Slater, who is nothing if not persistent in seeking the middle ground in the copyfight.

Update #2: "Smart cow" reference explained here.