Fair use is a legal doctrine only in the United States. It permits limited use of copyrighted material without acquiring permission from the rights holders. While often thought of as an affirmative defense, in Lenz v. Universal Music Corp, (the "dancing baby" case), the United States Court of Appeals for the Ninth Circuit concluded that fair use was not merely a defense to an infringement claim, but was an expressly authorized right, and an exception to the exclusive rights granted to the author of a creative work by copyright law. "Fair use is therefore distinct from affirmative defenses where a use infringes a copyright, but there is no liability due to a valid excuse, e.g., misuse of a copyright." Examples of fair use in United States copyright law include commentary, search engines, criticism, parody, news reporting, research, and scholarship. Although related, the limitations and exceptions to copyright for teaching and library archiving in the U.S. are located in a different section of the statute. Fair use provides for the legal, unlicensed citation or incorporation of copyrighted material in another author's work under a four-factor balancing test.