The DMCA is not the first provision in title 17 to mandate technological protection measures (TPMs). The first time I experienced this was in 1992, as copyright counsel to the House IP subcommittee. Hayden Gregory, the chief counsel of the subcommittee and I were charged with making was referred to jokingly as "DART-Lite", watering down the industry's version of what became the Audio Home Recording Act of 1992. Industry wanted the Serial Copy Management System (SCMS) to be mandated. We balked at mandating a private technology in public legislation, and so, Section 1002(a) refers to SCMS and to "a system that has the same functional characteristics as" SCMS.
DART, by the way, is a classic case of Congress being sold a phony bill of technological threats. We were told that the docks were loaded with these new fangled ditigal machines that would produce endless perfect copies from other copies. I saw no market for the digital audio cassettes contemplated by DART: adults would want CDs since they were hardly any more expensive, while kids would prefer analog cassettes given the much lower price.
And as for the "perfect copy claim," that claim was very powerful among members of Congress in the 1990s. Hayden and I actually insisted that the proponents send over from Japan a technician to demonstrate whether that was true; it turned out that after the 40th copy, there was an appreciable degradation.
Two other points, the utility of DART turned out to be of very short, limited value, while Section 1008, which was intended to take care of home copying once and for all, did no such thing. I wished we had killed the bill.
The issue of TPMs and whether the DMCA has fulfilled its purpose is being discussed on Randy Picker's mob. The mob is based on an article by Fred van Lohmann on the infamous Microsoft darknet paper. Here's the link to the discussion group: http://picker.typepad.com/picker_mobblog/