Supreme Court Rejects “Mere Knowledge” Standard for Contributory Copyright Infringement in Cox v. Sony, Reverses $1 Billion Judgment Against Cox

On March 25, 2026, in Cox Communications, Inc. v. Sony Music Entertainment, the U.S. Supreme Court reversed a $1 billion verdict against Cox. The judgment was the result of a jury trial in which Sony claimed that Cox was liable for contributory copyright infringement because it knew that its customers were using its service to infringe yet did not respond with sufficient diligence to prevent that infringement.

In a decision written by Justice Thomas and joined in full by six others (two concurred in the judgment), the Court held that an internet service provider (ISP) cannot be liable for contributory copyright infringement if all that is shown is that it knew that its service was being used to infringe. The Court held contributory infringement requires a showing that either (1) the ISP induced the infringement, or (2) the ISP was not capable of substantial or commercially significant non-infringing uses.

Background

Sony sued Cox in the U.S. District Court for the Eastern District of Virginia for violations of the Copyright Act, alleging (1) contributory liability because Cox continued to provide internet service to subscribers who it knew were engaged in copyright infringement, and (2) vicarious liability because Cox profited directly from subscribers' infringement while retaining the right and ability to supervise the direct infringers. The jury found in favor of Sony on both theories, found Cox's infringement willful, and awarded $1 billion in statutory damages.

The U.S. Court of Appeals for the Fourth Circuit affirmed as to contributory liability only and upheld the damages award. It reasoned that “supplying a product with knowledge that the recipient will use it to infringe copyrights is exactly the sort of culpable conduct sufficient for contributory infringement.” 93 F.4th 222, 236. The Fourth Circuit reversed as to vicarious liability, concluding that Cox did not receive a direct financial benefit from its subscribers’ infringement.

The Legal Framework

In reversing the Fourth Circuit, the Court noted, as it did in Sony Corp. of America v. Universal City Studios, Inc., 464 U.S. 417, 434 (1984), that the Copyright Act does not expressly “render anyone liable for infringement committed by another.” Rather, secondary liability is a matter of Supreme Court precedent. Given that Congress has not acted to expand the scope of liability, the Court was “loath to expand … liability beyond those precedents.” As such, the Court hewed to the scope of liability articulated in MGM Studios, Inc. v. Grokster, 545 U.S. 913 (2005) and Sony Corp. of America v. Universal City Studios, Inc., 464 U.S. 417 (1984). The Court thus held that an accused infringer is only liable for contributory liability when the accused infringer (1) induces the infringement, or (2) its service is tailored to that infringement, i.e., it is not capable of substantial or commercially significant non-infringing use.

Applying this standard, the Court concluded that the evidence adduced against Cox could not establish contributory infringement liability.

Justices Sotomayor and Jackson concurred in the judgment but disagreed with Justice Thomas’ reasoning.

Justices Sotomayor and Jackson agreed that Cox was not liable. They agreed that Cox could not be liable under the standard articulated by Justice Thomas.

But they concurred in the judgment rather than joining the majority’s opinion because they believed the majority’s standard was too narrow based on the Supreme Court’s prior cases, precluding other common-law bases for secondary liability, such as aiding and abetting liability.

In addition to deviating from prior precedent, this narrowing of liability, according to Justices Sotomayor and Jackson, “dismantles the statutory incentive structure Congress created in the Digital Millennium Copyright Act.” They noted that the DMCA provided ISPs “safe harbor” protections against claims of infringement provided that ISPs took reasonable steps to prevent infringement. They noted that, under the majority’s view, this safe harbor provision was rendered meaningless. According to Justices Sotomayor and Jackson, ISPs will have no incentive at all to monitor or prevent infringement.

To avoid this result, Justices Sotomayor and Jackson suggested application of an aiding and abetting theory of liability. Liability attaches under this theory on proof that an ISP “intended to aid, and therefore help make succeed, copyright infringement committed by those who use its network.”

Under this standard, the concurring justices found that there was still insufficient proof that Cox intended to aid or abet infringement. Rather, it was “merely” providing internet service and “[n]othing about that conduct is inherently culpable.” Moreover, the justices concluded that Sony failed to show that Cox intended to aid specific instances of infringement. This was so because, when Cox received a copyright violation notice, the notice only specified the connection used to infringe and not information concerning the actual infringer. “That informational gap [was] fatal” because aiding and abetting liability “often” requires proof that a defendant “knew who the ‘principals’ in the alleged unlawful acts were.”

In the end, the justices concluded that Cox could not be liable for secondary infringement because the evidence merely showed that Cox was “indifferent” to infringement. “Mere indifference … is not enough for aiding and abetting liability to attach.”

Crowell has been closely monitoring this important development in U.S. copyright law. We published an alert in October 2025 when the Supreme Court granted certiorari, and we will continue to monitor and provide updates as this area of the law develops.