ISPs Off the Hook: Supreme Court Narrows Contributory Copyright Liability
The U.S. Supreme Court unanimously held that knowledge of users' copyright infringement alone cannot support contributory liability against an internet service provider ("ISP").
On March 25, 2026, the Supreme Court reversed a billion-dollar verdict against Cox Communications, holding that an ISP "is contributorily liable for a user's infringement only if it intended that the provided service be used for infringement." Cox Communications, Inc. v. Sony Music Entertainment, No. 24-171, 607 U.S. ____ (2026). Writing for seven justices, Justice Thomas explained that contributory liability requires proof that an ISP either induced infringement by actively encouraging it or provided a service tailored to infringement, meaning one not capable of substantial noninfringing uses. Mere knowledge that some users will infringe is not enough.
Over a two-year period, Cox received more than 163,000 notices identifying IP addresses associated with infringement, yet terminated only 32 accounts. The Fourth Circuit affirmed the jury's finding of contributory liability, reasoning that supplying a service with knowledge that the recipient will use it to infringe is sufficient. The Supreme Court reversed, observing that "Cox simply provided Internet access, which is used for many purposes other than copyright infringement." The Court held that Cox did not induce its subscribers to infringe, nor did it provide a service tailored to infringement, and thus, neither basis for contributory liability was satisfied. The Court also rejected the argument that the Digital Millennium Copyright Act safe harbor presumes ISP liability for serving known infringers, noting that the safe harbor creates defenses from liability rather than imposing it.
Justice Sotomayor concurred in the judgment, as she would have recognized an additional theory of aiding-and-abetting liability for copyright infringement.
The decision is an immediate victory for ISPs. On April 6, 2026, the Supreme Court vacated a $46.7 million verdict against a Texas-based ISP that had been found liable under the same contributory infringement theory and remanded the case to the Fifth Circuit for further consideration in light of Cox.
The decision also has implications for artificial intelligence ("AI") copyright litigation. In some of these pending cases, plaintiffs have asserted contributory infringement claims based on infringing outputs generated by end users using the AI tools developed by defendants. Defendants may invoke Cox to argue that inducing infringement is a high bar and that merely training AI models on copyrighted material does not clear it. Plaintiffs, however, may counter that, unlike ISPs passively providing a connection, AI defendants not only trained their models on the plaintiffs' works, but also made deliberate design choices affecting the output. Whether that conduct satisfies Cox's standard for contributory liability remains an open question, and how courts resolve that question in any particular case will likely vary depending on the factual evidence presented.
