Opinion of the Court
Justice Souter delivered the opinion of the Court.
The question is under what circumstances the distributor of a product capable of both lawful and unlawful use is liable
Darrell V. McGraw, Jr., of West Virginia, and Peg Lautenschlager of Wisconsin; for the American Federation of Musicians of the United States and Canada et al. by George H. Cohen, Patricia Polach, and Laurence Gold; for the American Society of Composers, Authors and Publishers et al. by I. Fred Koenigsberg, Michael E. Salzman, and Marvin L. Berenson; for Americans for Tax Reform by Carter G. Phillips, Alan Charles Raul, Jay T. Jorgensen, and Eric A. Shumsky; for the Commissioner of Baseball et al. by Robert Alan Garrett and Hadrian R. Katz; for Defenders of Property Rights by Theodore B. Olson, Thomas H. Dupree, Jr., Matthew D. McGill, Nancie G. Marzulla, and Roger Marzulla; for International Rights Owners by Christopher Wolf; for Kids First Coalition et al. by Viet D. Dinh; for Law Professors et al. by James Gibson; for Macrovision Corp. by Geoffrey L. Beauchamp, Kelly G. Huller, and James H. Salter; for Napster, LLC, et al. by Barry I. Slotnick; for the National Academy of Recording Arts & Sciences, Inc., et al. by Jon A. Baumgarten and Jay L. Cooper; for the National Association of Broadcasters by Marsha J. MacBride, Jane E. Mago, Benjamin F. P. Ivins, and Jerianne Timmerman; for the National Association of Recording Merchandisers by Alan R. Malasky and Melanie Martin Jones; for the Progress & Freedom Foundation by James V. DeLong; for the Video Software Dealers Association by John T. Mitchell; and for Professor Peter S. Menell et al. by Mr. Menell, pro se. Briefs of amici curiae urging affirmance were filed for Altnet, Inc., by Roderick G. Dorman; for the American Civil Liberties Union et al. by Christopher A. Hansen, Steven R. Shapiro, Sharon M. McGowan, Ann Brick, and Jordan C. Budd; for the American Conservative Union et al. by David Post; for the Cellular Telecommunications & Internet Association et al. by Andrew G. McBride, Joshua S. Turner, Michael Altschul, James W. Olson, Frank L. Politano, Laura Kaster, Jeffrey A. Rackow, Grier C. Raclin, Michael Standard, John Thorne, Sarah B. Deutsch, and Paul J. Larkin, Jr.; for the Consumer Electronics Association et al. by Bruce G. Joseph and Scott E. Bain; for the Consumer Federation of America et al. by Peter Jaszi; for the Distributed Computing Industry Association by Mr. Dorman; for the Eagle Forum Education & Legal Defense Fund by Andrew L. Schlafly and Karen B. Tripp; for the Free Software Foundation et al. by Eben Moglen; for Intel Corp. by James M. Burger and Jonathan D. Hart; for Internet Law Faculty by William W. Fisher III and Jonathan Zittrain; for Law Professors by J. Glynn Lunney, Jr.; for the National Association of Shareholder and Consumer Attor-
