The doctrine forbids the copyright owner from attempting to secure an exclusive right or limited monopoly (usually through restrictive licensing practices) that is not granted by federal copyright law and is contrary to public policy. Finding that a copyright owner has engaged in misuse prevents the owner from enforcing his copyright through the securing of an injunction until he has "purged" himself of the misuse i.e., ceased the restrictive practices.
Copyright misuse is not a defense recognized in the provisions of the federal Copyright Act but is instead purely founded in federal case law, beginning with a case in the Minnesota Federal District Court, M. Witmark & Sons v. Jensen, 80 F. Supp. 843 (D. Minn. 1948). The doctrine later met with approval from the Fourth Circuit in Lasercomb v. Reynolds, 911 F.2d 970 (4th Cir. 1990). Other leading cases in the area include Video Pipeline, Inc. v. Buena Vista Home Entertainment, 342 F.3d 191 (3d Cir. 2003), Assessment Technologies v. WIREdata, 350 F.3d 640 (7th Cir. 2003), and Int'l Motor Contest Assoc. Inc. v. Staley, No. 05-3080, N.D. Iowa June 19, 2006.
Copyright misuse is derived from the longstanding equitable doctrine of "unclean hands", which bars a party from asking for equitable relief (such as an injunction) against another when they have themselves acted improperly (though not necessarily illegally). Improper behaviour that may lead to a finding of copyright misuse includes (but is not limited to) anti-competitive activity.