If your ISP can be liable for huge amounts of money for not terminating your access to the internet because of accusations that you—or someone in your household or college network—has committed copyright infringement, that is dangerous. We live in a world where high speed internet access is a necessity for participation in everyday life. That’s why liability for ISPs for their customers’ actions should not be expanded.

Last fall, EFF filed an amicus brief urging the U.S. Supreme Court to reject an expansive theory of secondary copyright liability that threatened to impose massive damages on internet service providers and other technology companies simply for offering widely used services. Yesterday, the Court agreed.

In Cox v. Sony, the Court reversed a Fourth Circuit decision that had upheld a billion-dollar verdict against internet provider Cox Communications. Writing for the majority, Justice Thomas explained that contributory liability is limited to two situations: when a defendant actively induces infringement, or when it provides a product or service that it knows is tailored for infringement.

This framework closely tracks the approach EFF urged in our amicus brief. As we explained, courts should look to patent law for guidance in defining the boundaries of secondary copyright liability. Patent law recognizes liability where a defendant actively induces infringement, or distributes a product knowing that it lacks substantial non-infringing uses. The Court’s opinion adopts that same basic structure.

EFF also emphasized the broader public interest at stake in preserving these limits. Expansive theories of secondary liability do not just affect large internet providers. They can chill innovation, threaten smaller technology companies, and undermine the development of general-purpose tools that millions of people rely on for lawful speech, creativity, education, and access to information. When liability turns on generalized knowledge that some users may infringe, service providers face pressure to over-police user activity or withdraw useful services altogether.

The Court also made clear that mere knowledge that some customers use a service to infringe is not enough. Copyright holders must show that the provider intended its service to be used for infringement. That intent can be established only through active inducement or by showing that the service is specifically designed for unlawful uses—not simply because the service provider failed to take affirmative steps to prevent infringement.

Applying this standard, the Court held that Cox could not be liable. There was no evidence that Cox encouraged or promoted infringement. The record instead showed that Cox implemented warning systems, suspended service, and in some cases terminated accounts in an effort to discourage unlawful activity.

Nor was Cox’s internet access service tailored to infringement. The Court emphasized that general-purpose internet connectivity is capable of substantial lawful uses. Treating the provision of such services as contributory infringement would improperly expand secondary liability beyond the limits recognized in prior Supreme Court decisions.

The Court also rejected the Fourth Circuit’s broader rule that supplying a service with knowledge it may be used to infringe is itself sufficient for liability. That theory conflicts with decades of precedent warning against imposing copyright liability based solely on knowledge or a failure to take additional preventive steps.

EFF is pleased with yesterday’s opinion. We will continue to advocate for the public’s ability to build, use, and innovate with new technologies.

Link to our amicus brief: 
https://www.eff.org/document/us-s-ct-cox-v-sony-eff-et-al-amicus-brief

Link to the opinion:
https://www.supremecourt.gov/opinions/25pdf/24-171_bq7d.pdf