C.E. Petit, a prominent IP lawyer who's represented Harlan Ellison in a number of piracy cases, talks sense over at Scrivener's Error:
The underlying difficulty is that DRM is inherently an inept solution to the basic problem, no matter how elegantly implemented; the problem extends far beyond limitations on (or expansion of) fair use. Instead, this is a matter of economics and price points.
This is a point that comes up again and again in studies of file sharing; people don't want to pay a premium for a CD with only one or two tracks they'll actually listen to. In addition, there's an issue of goodwill involved; when consumers consistently find themselves buying $14-$18 albums for one or two radio hits, it's not unreasonable for them to feel like they're being cheated.
Mr. Petit continues:
This points out the economic model for preventing (or combatting) piracy: The perceived quality and availability of the genuine article must substantially exceed the premium over the counterfeit [...] All of this implies that instead of DRM, the media giants need to take a close look at their pricing structures, accounting, release timing, and value added to physical products.
In other words, if you can give people positive incentives (worthwhile extras, the sense that they're not being ripped off) to buy your product instead of pirate it, they'll do so. Funny how that works.