“Contributory liability cannot rest only on a provider’s knowledge of infringement and insufficient action to prevent it.” – Justice Clarence Thomas
The U.S. Supreme Court on Wednesday reversed a decision by the U.S. Court of Appeals for the Fourth Circuit, ruling that internet service provider Cox Communications, Inc., is not contributorily liable for its subscribers’ copyright infringement. In a 7-2 decision authored by Justice Thomas, the Court held that a service provider is contributorily liable for a user’s infringement only when it intended for its service to be used in that way, which is established only if the provider either encouraged the infringement or designed the service specifically to facilitate it.
Cox Communications, Inc. v. Sony Music Entertainmentoriginates from a lawsuit filed by Sony Music Entertainment and other major music copyright owners against Cox in the United States District Court for the Eastern District of Virginia. Sony enlisted MarkMonitor to track copyright infringement across the internet. During the roughly two-year period at issue, MarkMonitor sent Cox 163,148 notices identifying IP addresses of Cox subscribers associated with infringement.
A jury in the district court found in favor of Sony on both contributory and vicarious liability theories, found Cox’s infringement willful, and awarded $1 billion in statutory damages. The Fourth Circuit affirmed as to contributory liability, reasoning that “supplying a product with knowledge that the recipient will use it to infringe copyrights is exactly the sort of culpable conduct sufficient for contributory infringement.” The Fourth Circuit reversed as to vicarious liability, and the Supreme Court granted certiorari only as to contributory liability.
In its opening brief filed in August 2025, Cox argued that the Fourth Circuit’s holding “flouts a century of this Court’s case law” by imposing contributory liability without proof of culpable conduct, and that internet service providers should not be turned into “internet police.” The Court later granted the U.S. Solicitor General’s motion to participate as an amicus in oral argument, allowing the government to weigh in at the December 1 hearing. During that oral argument, the justices had tough questions for both sides, with Justice Sonia Sotomayor characterizing the arguments as proposing two “extremes” and asking how the Court could announce a rule that addresses those extremes.
Justice Thomas explained that the “Copyright Act does not expressly render anyone liable for infringement committed by another.” The Court has recognized two categories of secondary liability with contributory liability and vicarious liability. Since the case concerned contributory liability, the Court focused on whether Cox intended its service to be used for infringement.
A copyright owner can show the requisite intent in two ways, either by demonstrating that a party affirmatively induced the infringement or that it sold a service tailored to infringement, but the Court found that Cox did neither.
As for inducement, the Court noted that Cox did not “induce” or “encourage” its subscribers to infringe in any manner. Sony provided no “evidence of express promotion, marketing, and intent to promote infringement.” Furthermore, Cox repeatedly discouraged copyright infringement by sending warnings, suspending services, and terminating accounts.
As for providing a service tailored to infringement, the Court stated that Cox’s internet service was clearly “capable of ‘substantial’ or ‘commercially significant’ noninfringing uses.” Cox simply provided internet access, which is used for many purposes other than copyright infringement.
The Court rejected the Fourth Circuit’s reasoning, stating that its holding went beyond the two forms of liability recognized in previous cases, such as Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd. and Sony Corp. of America v. Universal City Studios, Inc. The Fourth Circuit’s holding also conflicted with the Court’s repeated admonition that “contributory liability cannot rest only on a provider’s knowledge of infringement and insufficient action to prevent it.”
Sony argued that the Digital Millennium Copyright Act (DMCA) safe harbor would have no effect if internet service providers are not liable for providing internet service to known infringers. The DMCA safe harbor protects internet service providers that terminate repeat infringers “in appropriate circumstances.” However, the Court determined that Sony overread the DMCA, which does not expressly impose liability on internet service providers who serve known infringers but instead creates new defenses from liability for such providers.
Justice Sotomayor, joined by Justice Ketanji Brown Jackson, filed an opinion concurring only in the judgment. Justice Sotomayor agreed that Cox is not liable, but argued that the majority unnecessarily limited secondary liability. She said that the Court’s precedents leave open the possibility that “other common-law theories, such as aiding and abetting, could apply in the copyright context.”
“The majority’s limiting of secondary liability here dismantles the statutory incentive structure that Congress created,” Sotomayor said.
