In an opinion released yesterday authored by Judge Frank Easterbrook, the Seventh Circuit rejected the fair use defense asserted by a defendant who had used KaZaA to download copyrighted music files. The entire opinion in BMG Music v. Gonzalez is worth reading, but here is an excerpt:

  Copyright law lets authors make their own decisions about how best to promote their works; copiers such as [the defendant] cannot ask courts (and juries) to second-guess the market and call wholesale copying "fair use" if they think that authors err in understanding their own economic interests or that Congress erred in granting authors the rights in the copyright statute. Nor can she defend by observing that other persons were greater offenders; [the defendant]'s theme that she obtained "only 30" (or "only 1,300") copyrighted songs is no more relevant than a thief's contention that he shoplifted "only 30" compact discs, planning to listen to them at home and pay later for any he liked.

  Thanks to Eric Goldman for the link.