Fair Use

Under U.S. copyright law, fair use protects the public against overly-aggressive copyright holders, and the doctrine is probably required by the [[free speech clause]].

Fair use is not considered copyight infringement. 17 U.S.C. § 107 specifies that, notwithstanding the enumerated exclusive rights of the copyright holder, "fair use … is not an infringement of copyright". Despite this statutory language, it is usually treated as an [[affirmative defense]], placing the burden on the defendant to prove fair use, with one notable exception.

In the DMCA [[notice-and-takedown]] context, the prevailing view is that the copyright owner must have a good faith belief that the allegedly infringing use is not fair before sending a takedown notice. See Lenz v. Universal Music Corp., 815 F.3d 1145, 1152-53 (9th Cir. 2016).

The required (non-exhaustive) fair use factors are:

1. the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
2. the nature of the copyrighted work;
3. the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
4. the effect of the use upon the potential market for or value of the copyrighted work.