IP Hot Topic: Supreme Court Reshapes Contributory Copyright Liability in Cox v. Sony Music: What It Means for Copyright Owners, Platforms, and ISPs

On March 25, 2026, the Supreme Court unanimously reversed the Fourth Circuit’s judgment in Cox Communications v. Sony Music Entertainment and held that Cox cannot be held contributorily liable for its subscribers’ infringement of Sony’s copyrights.

The Majority Opinion

According to the Court, an internet service provider (ISP) may not be contributorily liable for copyright infringement merely because it continues to provide service to known infringers. Under the Court’s precedents in Grokster and Sony, contributory copyright liability requires intent that the service be used for infringement, and that intent can be shown only in two ways: (1) affirmative inducement of infringement, such as by actively encouraging infringing conduct, or (2) provision of a service tailored to infringement, meaning a service incapable of substantial noninfringing uses.

Applying this framework, the Court determined that Cox did not induce infringement. Cox did not encourage, market, or promote infringing use and instead repeatedly warned subscribers, suspended service, and terminated accounts. Nor was Cox’s internet service tailored to infringement. Cox simply provided general internet access, which is capable of substantial lawful uses. The Court criticized the Fourth Circuit’s contrary holding, explaining that it went beyond the two forms of contributory liability recognized in Grokster and Sony and conflicted with the Court’s repeated rejection of liability based solely on a provider’s knowledge of and failure to do more to prevent it.

The Court’s framework closely tracked the Solicitor General’s position that contributory copyright liability requires culpable intent, not mere knowledge coupled with continued service. The Court also largely adopted the Solicitor General’s readings of Sony, Grokster, and the DMCA—particularly the rejection of the Fourth Circuit’s “knowledge equals intent” theory and the clarification that the DMCA safe harbor does not imply liability outside its terms.

The Concurring Opinion

Justice Sotomayor, joined by Justice Jackson, agreed with the result—that Cox is not liable—but criticized the majority for going further than necessary. In her view, the majority unnecessarily narrowed contributory copyright liability by limiting a court’s ability to consider other established common‑law theories of secondary liability, such as aiding and abetting.

Impact on Legal Practice

Cox v. Sony meaningfully raises the bar for secondary copyright liability and narrows the theories available to plaintiffs against intermediaries and technology providers. The decision reinforces a brightline intent requirement, limiting contributory liability to cases involving affirmative inducement or services designed or tailored for infringement, and rejecting liability based on knowledge plus inaction alone. As a result, the ruling curtails expansive negligence and “should‑have‑done‑more” theories, potentially shifting copyright enforcement toward direct infringers or actors who actively promote infringement.

Implications for Generative AI Companies

The Court’s decision is likely to constrain secondary copyright liability theories against generative AI companies whose software may be used to generate infringing outputs. By reaffirming that contributory liability requires intent, shown only through affirmative inducement or the provision of a service tailored to infringement, the Court rejects liability based merely on knowledge that a technology can be misused.

Generative AI systems—like general‑purpose internet access in Cox—are typically capable of extensive lawful, noninfringing uses and are not designed exclusively or predominantly to infringe copyrights. Absent evidence that a generative AI developer actively encourages infringing uses (for example, by marketing the system as a tool for reproducing copyrighted works) or designs the system so that infringement is its principal or unavoidable function, Cox strengthens the argument that awareness of downstream infringement, standing alone, is insufficient to establish contributory copyright liability.

Practical Takeaways

For Copyright Owners. Copyright owners should advance more targeted theories of contributory infringement and be prepared to point to evidence of culpable intent, such as marketing materials encouraging infringing uses or product features designed to facilitate infringement.

For ISPs and Platform Providers. Providers should ensure that marketing, product design, and internal practices do not encourage infringing uses, and should maintain reasonable repeat-infringer policies to preserve defenses and manage litigation risk.