On March 25, 2026, the Supreme Court issued a decision in Cox Communications, Inc. v. Sony Music Entertainment with significant implications for both rightsholders and parties accused of copyright infringement based on their users’ activity.

Sony and other major music labels sued Cox, an internet service provider, after sending over 163,000 infringement notices that Cox, according to Sony, failed to adequately address, terminating only 32 subscribers for infringement during the relevant period. A jury in the Eastern District of Virginia found Cox liable for willful contributory infringement and awarded $1 billion in damages.

In a 9-0 decision, the Supreme Court found that Cox was not contributorily liable for the actions of its users, reversing the Fourth Circuit’s decision upholding the verdict. Justice Thomas, writing for the majority, held that an ISP is contributorily liable “only if it intended” that the service be used for infringement and that “[t]he intent required for contributory liability can be shown only if the party induced the infringement or the provided service is tailored to that infringement.” Justice Sotomayor (joined by Justice Jackson) concurred on the ground that, while Cox’s conduct did not meet any standard for contributory liability, the majority’s limitation of secondary liability to those two scenarios was unwarranted. Justice Sotomayor would have left open common-law theories of secondary liability for copyright infringement.

Although the implications of the ruling have yet to be seen, Cox has the potential to weakens the leverage that copyright holders have over internet service providers and other parties accused of contributory infringement. Notably, the majority rejected the argument that DMCA safe harbor was enacted “on the presumption that Internet service providers could be held liable in cases such as these,” holding instead that “[t]he DMCA merely creates new defenses from liability for such providers.” Thus, as a practical matter, the decision has the potential to substantially weaken the incentive for ISPs and platforms to cooperate and shifts the enforcement burden back onto rightsholders.