Interesting legal strategy from Charlie Nesson in the Tenenbaum case, via Ray Beckerman:
Tenenbaum's team has moved to amend the defendant's answer, offering only the single affirmative defense of fair use. The proposed answer (PDF) also includes two previous counterclaims: abuse of federal process and state process. Ray notes there are at least six viable other affirmative defenses.
In the motion for leave to amend (PDF), the defendant says it's all about fair use:
Infringement is the copying of a copyrighted work that is not a fair use. The Plaintiffs have the burden of proving infringement and, therefore, the burden of proving that Joel Tenenbaum’s use was not fair. Defendant Tenenbaum does not mean to compromise this fundamental procedural position imposing on the Plaintiffs the burden of proving infringement by pleading fair use as an affirmative defense. Defendant Tenenbaum pleads fair use at this point and in this way only to make explicit his intention to contest the issue of fair use at trial.