primary purpose or effect. Copyright. The main reason for or consequence of using a product, as a test for whether its sale amounts to contributory negligence. • The Supreme Court rejected the test in a landmark copyright case, but four justices said that if the primary purpose or effect of the product’s sale or use infringes the copyrights of others, its manufacturer could be enjoined from selling the product or required to pay a reasonable royalty to the copyright owners.Sony Corp. of Am. v. Universal City Studios, Inc., 464 U.S. 417, 457–500, 104 S.Ct. 774, 796–818 (1984) (Blackmun, J., dissenting). Cf. COMMERCIALLY SIGNIFICANT NONINFRINGING USE.

[Blacks Law 8th]