Fair use
Fair use is a legal doctrine under United States copyright law permitting limited use of copyrighted material without the copyright holder's permission for purposes such as criticism, comment, news reporting, teaching, scholarship, or research.[1] The doctrine originated in common law, notably articulated by Justice Joseph Story in the 1841 case Folsom v. Marsh, which emphasized evaluating the quantity and value of the material used relative to the whole work to avoid unjust prejudice to the copyright owner.[2] Codified in Section 107 of the Copyright Act of 1976, fair use is determined on a case-by-case basis through four statutory factors: the purpose and character of the use (including whether it is transformative or commercial); the nature of the copyrighted work; the amount and substantiality of the portion used in relation to the whole; and the effect of the use on the potential market for or value of the original work.[1][3] This framework seeks to balance the exclusive rights of copyright owners with the public's interest in the free dissemination of ideas, though its application remains inherently fact-specific and frequently contested in litigation.[4]