Supreme Court Hears Cox v. Sony in a Battle Over ISP Responsibility for Copyright Abuse
On December 1, 2025, the Supreme Court held oral argument in Cox Communications, Inc. v. Sony Music Entertainment, which raises a question of what is required to hold an internet service provider (“ISP”) liable for the copyright infringement of its subscribers.
The core issue in this case is whether ISPs may be held liable for contributory copyright infringement for failing to terminate the internet service of a customer the ISP knows is using the service to commit copyright infringement. The Supreme Court granted certiorari after the Fourth Circuit upheld a billion dollar jury verdict against Cox. The Fourth Circuit determined that all that was required to establish liability for contributory copyright infringement was that the ISP failed to terminate internet service despite knowing that infringing activity was “substantially certain” to occur in the future.
At oral argument, the Court did not seem inclined to adopt either side’s position (both of which Justice Sotomayor described as “extreme”). Some justices were concerned that Cox’s position—that ISPs could be held liable only if they induced infringement or took an affirmative act to promote infringement—would render the Digital Millennium Copyright Act’s (“DMCA”) safe harbor provision unnecessary surplusage. Specifically, the safe harbor provision affords protection from copyright liability only to ISPs that meet certain requirements, including establishing a policy to terminate accounts of repeat infringers and providing a mechanism for copyright holders to submit notices of infringement to the ISP. If liability attached only in cases of inducement or affirmative promotion of infringement, it would have been incongruous of Congress to include the safe harbor provision.
Justices Barrett and Jackson both emphasized that Congress’s intent in adopting the DMCA was to encourage ISPs to address and take proactive steps to prevent copyright infringement. They both expressed concern regarding whether ISPs would still have any incentive to combat infringement if the Court adopted Cox’s position, which Justice Jackson opined would “essentially eliminate liability” for ISPs.
On the other side, the justices pushed back significantly on Sony’s argument that contributory liability did not require any showing that the wrongdoer wanted the infringement to occur. The Court was also skeptical that Sony’s position—that liability arises when an ISP continues to provide internet service while knowing that infringement is “substantially certain” to follow—was workable. Consider, for example, that some customers of ISPs, such as universities, hotels, and hospitals, can have tens of thousands of users that are constantly changing. Justice Alito sharply questioned Sony regarding how ISPs should address those situations to avoid liability short of terminating service to thousands of non-infringing users. Justice Kagan also questioned whether holding ISPs liable based on mere knowledge of infringement might encourage ISPs to stop assisting copyright holders to prevent infringing activities or to remain intentionally ignorant about such infringing activities.
Several justices also raised questions regarding the scope of the cause of action for contributory copyright infringement (which is implied rather than expressly provided by statute). This suggests that the Court may narrowly define the cause of action and leave the issue of whether to expand the grounds for contributory liability to Congress.
Ultimately, while the Court expressed some skepticism as to both parties’ positions, the questioning generally suggested that the Court is suspicious of the billion-dollar judgment, and is likely to conclude that something more than mere knowledge is required to establish contributory copyright infringement. Regardless of how this case is decided, it is expected to provide needed guidance in this uncertain area of law.