Page:United States Reports, Volume 545.djvu/982

 Opinion of the Court enforce rights in the protected work effectively against all direct infringers, the only practical alternative being to go against the distributor of the copying device for secondary liability on a theory of contributory or vicarious infringement. See In re Aimster Copyright Litigation, 334 F.3d 643, 645–646 (CA7 2003).

One infringes contributorily by intentionally inducing or encouraging direct infringement, see ''Gershwin Pub. Corp. v. Columbia Artists Management, Inc., 443 F.2d 1159, 1162 (CA2 1971), and infringes vicariously by profiting from direct infringement while declining to exercise a right to stop or limit it, Shapiro, Bernstein & Co. v. H. L. Green Co.'', 316 F.2d 304, 307 (CA2 1963). Although “[t]he Copyright Act does not expressly render anyone liable for infringement committed by another,” Sony Corp. v. Universal City Studios, 464 U.S., at 434, these doctrines of secondary liability emerged from common law principles and are well established in the law, id., at 486 (Blackmun, J., dissenting); Kalem Co. v. Harper Brothers, 222 U.S. 55, 62–63 (1911); ''Gershwin Pub. Corp. v. Columbia Artists Management,''