The Internet on Trial: Contributory Liability for ISPs Heads to the Supreme Court

In Cox Communications v. Sony, the Court is expected to address two core issues: whether knowingly providing internet services to users committing copyright infringement and not terminating access constitutes a “material contribution,” thereby making the ISP liable for contributory copyright infringement and whether, in secondary liability cases, “willfulness” under 17 U.S.C. § 504(c) can be satisfied by the defendant’s knowledge of subscribers’ direct infringement, or whether it requires knowledge or reckless disregard that the defendant’s own conduct is unlawful. The decision is likely to influence risk allocations among ISPs, online platforms, and copyright owners in a landscape defined by ubiquitous connectivity and large-scale content sharing.

Background and Procedural Posture

In 2018, more than 50 music industry plaintiffs — including affiliates of Sony, Universal, and Warner — sued Cox Communications in the Eastern District of Virginia, alleging wide-scale peer-to-peer sharing of copyrighted music by Cox subscribers. Following a 12-day jury trial, the jury found Cox liable for contributory and vicarious infringement and awarded $1 billion in statutory damages. The district court denied Cox’s post-trial motions, finding that Cox had knowledge of specific infringing activity through notices it received and materially contributed to that activity by continuing to provide high-speed internet access that was “essential” to the infringement.

On appeal, the Fourth Circuit affirmed the contributory infringement verdict and vacated the vicarious liability verdict. The Supreme Court granted certiorari on June 30, 2025, to review questions concerning the knowledge and material contribution elements of contributory infringement in the ISP context.

The Fourth Circuit’s Approach to Contributory Liability

The Fourth Circuit held that a contributory infringement claim requires proof that the defendant had knowledge of specific infringement and materially contributed to it. On knowledge, the court concluded Cox knew that certain subscribers were “substantially certain” to engage in infringing activity based on detailed notices received from rights holders. On material contribution, the court rejected the proposition that a service with substantial lawful uses cannot materially contribute to infringement. The court focused instead on whether the service was provided with awareness of specific infringing uses and whether the provider took steps — or declined to take steps — consistent with limiting access for known infringers. Drawing an analogy to aiding and abetting principles, the court reasoned that continuing to provide the means of infringement to identified repeat offenders can satisfy material contribution.

Supreme Court Precedent and the Doctrinal Landscape

The Court’s 2005 decision in MGM v. Grokster emphasized inducement liability, holding that a distributor who promotes the use of a device or service to infringe copyright may be liable for resulting infringement. Grokster distinguished mere knowledge of infringing potential or actual infringing uses from affirmative steps designed to foster infringement. While Grokster centered on inducement, lower courts have continued to develop contributory liability tests that examine knowledge and material contribution even where a product or service has substantial non-infringing uses, and vicarious liability tests that focus on right and ability to control and direct financial benefit.

The Cox case invites the Court to clarify how these doctrines interact for intermediaries whose core service — network access — enables both lawful and unlawful activity. It also raises questions about the relationship between notice regimes and knowledge standards, and about what operational responses, such as account termination, throttling, or other mitigation, are sufficient to avoid a finding of material contribution.

Practical Stakes for Stakeholders

For ISPs and network operators, the decision may influence what constitutes adequate repeat infringer policies, the sufficiency of notice-and-action protocols, and the extent to which continued service to notified subscribers can be deemed a material contribution. A ruling lowering the threshold for knowledge or broadening material contribution could press ISPs toward more aggressive escalation, including account suspensions or terminations, with implications for customer experience, compliance costs, and dispute resolution processes.

For online platforms, cloud providers, content delivery networks, and virtual private networks, the reasoning could cascade into broader expectations for how intermediaries respond to detailed infringement notices, the design and documentation of enforcement workflows, and the balance between preventing misuse and preserving legitimate access. Even if the holding is framed for ISPs, its logic may be cited in other contexts where intermediaries provide infrastructure used by end users for both lawful and unlawful purposes.

For institutions relying on shared connections — schools, hospitals, libraries, enterprises, multi-family housing, and rural communities — the case highlights operational risk in managing network accounts that serve multiple users. If stricter termination practices become the norm in response to rights-holder notices, shared-account environments may face heightened exposure to service disruptions absent clear internal policies, user education, and mechanisms to isolate or remediate infringing activity without broad outages.

For rights holders, a decision affirming the Fourth Circuit could strengthen the leverage of detailed, well-documented notice programs and incentivize collaboration with ISPs to align notice formats and escalation pathways. A decision narrowing contributory liability could, conversely, prompt greater investment in direct enforcement against end users, and technical measures to deter infringement.

Key Issues to Watch at Oral Argument

How the Court Frames Knowledge: Look for whether the justices distinguish among actual knowledge of specific infringement, willful blindness, and generalized awareness of infringing activity on a network, and how those distinctions map to enhanced statutory damages for willful infringement.

How the Court Conceptualizes Material Contribution for Network Services: The justices may probe whether continued provision of baseline connectivity to notified subscribers suffices, or whether additional factors, such as inducement, targeted support, or refusal to implement reasonable mitigation, are required.

How Grokster Is Used and Limited: Expect debate over the applicability of inducement principles to a connectivity provider, and how Grokster’s emphasis on “affirmative steps” interacts with passive service provision coupled with notice.

Operational Safe Harbors and Policy Design: While statutory safe harbors are distinct, oral argument may explore how repeat infringer policies, notice processing, and appeals protocols bear on knowledge and contribution. The Court’s discussion could influence industry norms even if not formalized in the opinion.

Preparing for Potential Outcomes

ISPs should consider reviewing their notice intake and response processes, repeat infringer policies, and documentation of escalation decisions. Clarifying roles and responsibilities with resellers and managed service partners, evaluating data retention and logging practices tied to notice events, and ensuring fair, transparent subscriber communications and appeals can mitigate exposure while maintaining service quality. Institutions with shared accounts may benefit from technical segmentation, user education, and defined remediation pathways to avoid broad disruptions when issues arise.

Rights holders may wish to assess the specificity, reliability, and format of their notices; invest in systems that facilitate secure, verifiable information exchange with intermediaries; and evaluate the evidentiary sufficiency of their programs to support knowledge claims if litigation becomes necessary.

Conclusion

Cox v. Sony presents the Supreme Court with an opportunity to clarify the contours of contributory liability in the context of network access. Whatever the outcome, careful attention to policy design, documentation, and measured operational responses will be essential for stakeholders navigating the evolving legal framework.