464 U.S. 417 (1984)
Sony v. Universal City Studios, often called the Betamax case, is a cornerstone of modern copyright law at the intersection of creativity, consumer behavior, and technological innovation.
1) Is private, noncommercial home time-shifting of free, over-the-air television broadcasts a fair use under 17 U.S.C. § 107? 2) Can a manufacturer be held contributorily liable for copyright infringement based on the sale of a device that is capable of substantial noninfringing uses?
A defendant who distributes a device does not incur contributory copyright liability merely because the device can be used to infringe, so long as the device is capable of substantial noninfringing uses. In addition, under 17 U.S.C. § 107, private, noncommercial home time-shifting of television broadcasts may constitute fair use; when the use is noncommercial, the copyright owner bears the burden to demonstrate a likelihood of market harm to negate fair use. The four statutory fair use factors apply, with market effect often the most important.
The Supreme Court reversed the Ninth Circuit. It held that private, noncommercial home time-shifting of free, broadcast television programs is fair use. Because the Betamax VCR is capable of substantial noninfringing uses, Sony is not liable for contributory infringement based on its sale.
Sony crystallizes two enduring doctrines. First, it is a leading fair use case: noncommercial home time-shifting of broadcasts can be fair use absent a showing of market harm. Second, it establishes the "Sony doctrine" for secondary liability: a technology provider is not contributorily liable if its device is capable of substantial noninfringing uses. This shield protects innovators from being held hostage to unlawful uses by some consumers, unless they induce infringement or their product lacks meaningful lawful uses. The case remains central in technology and copyright litigation. Courts have distinguished or built upon Sony in cases involving peer-to-peer networks (e.g., inducement liability in MGM v. Grokster), digital music services, and cloud DVRs. For law students, Sony exemplifies statutory interpretation of § 107, allocation of burdens in fair use analysis, and policy-sensitive limits on secondary liability to avoid chilling innovation.