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.