Intellectual Property Blog

When Knowledge Isn’t Enough: What Cox v. Sony Means for DMCA Agents

Can an online service provider be held liable for copyright infringement simply because it knows infringement is occurring and does not immediately terminate a user’s access? On March 25, 2026, the U.S. Supreme Court answered that question with a decisive no, delivering a unanimous opinion.

In Cox Communications, Inc. v. Sony Music Entertainment, the court reversed the Fourth Circuit’s holding that Cox was contributorily liable for its subscribers’ infringement based largely on its receipt of more than 160,000 DMCA notices and its alleged failure to terminate repeat infringers. At trial, a jury had found Cox’s conduct willful and awarded $1 billion in statutory damages. Although the Fourth Circuit had already vacated that damages award, the jury’s finding that Cox was contributory liability for others’ infringement remained until now.

Justice Clarence Thomas, writing for the Court, reaffirmed a critical boundary in secondary copyright liability: knowledge alone is not intent. Under longstanding precedent, a service provider is contributorily liable only if it intended its service to be used for infringement. That intent can be shown in two ways: (1) by affirmatively inducing infringement, or (2) by offering a service tailored to infringement because it lacks substantial non-infringing uses. The Supreme Court found that Cox did neither. Cox simply provided general-purpose internet access, a service with overwhelmingly legitimate uses.

For DMCA agents, this clarification is essential. The record showed that Cox implemented a tiered response system: forwarding notices, issuing warnings, suspending accounts, and terminating some users for repeat violations. The Court made clear that the DMCA does not require mass disconnections or zero-tolerance termination policies to avoid liability. Holding otherwise, the Court warned, would dangerously expand contributory infringement doctrine beyond its historical limits and threaten access to essential internet services.

Importantly, the Court separated contributory liability doctrine from the DMCA’s safe harbor framework. While repeat infringer policies remain a statutory requirement under Section 512 of the Copyright Act, the Cox decision confirms that imperfect enforcement of those policies does not amount to willful  infringement. For online platforms and their DMCA agents, this distinction preserves the ability to design reasonable, good-faith compliance programs without fear that every judgment call will later be interpreted as infringement facilitation, or worse.

Justice Sotomayor, joined by Justice Jackson, concurred in the judgment but cautioned that the majority’s reasoning may limit future development of secondary liability. Even so, the outcome was unanimous: Cox was not liable, and knowledge coupled with continued service is not enough.

Cox v. Sony reflects that DMCA compliance is assessed based on diligence in handling notice volumes, not on an expectation of perfect outcomes.  The Supreme Court made clear that internet service providers are not expected to cut off users wholesale in response to infringement allegations, and that the DMCA is meant to strike a workable balance between copyright enforcement and continued access to online services, not to impose automatic punishment.

Katherine Moore Donnelly is an Associate of McBrayer PLLC, practicing in the firm's Lexington office. Her law practice primarily focuses on intellectual property, DMCA Agent Services, and transactional matters. Ms. Donnelly can be reached at kdonnelly@mcbrayerfirm.com or (859) 231-8780.

Services may be performed by others. This article does not constitute legal advice.