What Cox v. Sony Changed—and What It Did Not

Cox Communications v. Sony Music changed the Fourth Circuit's rule for contributory copyright liability, but it did not create blanket immunity for Internet service providers. The Supreme Court held that knowledge that a connection is used for infringement, combined with continued service and imperfect prevention, does not by itself prove the intent required for contributory liability. This final synthesis connects the notice record, the network information gap, the two recognized routes to liability, and the separate DMCA safe-harbor system so the reader can apply the decision without turning it into either a free pass or a monitoring mandate.

The most defensible bottom line is precise: for ordinary general-purpose Internet access, a copyright owner must show more than awareness and continued provision of service. Under the majority's formulation, the evidence must show active inducement or a service tailored to infringement. The decision leaves other theories and policy questions open, but it raises the evidentiary threshold for converting knowledge of user conduct into contributory liability.

From a notice to a conclusion about intent

The reasoning begins with the kind of service and the kind of information available to its provider. Cox served approximately six million subscribers. An IP address could be associated with a subscriber account, but a household, coffee shop, dormitory, hospital, university network, or regional ISP could place many people behind the same connection. MarkMonitor's notices identified IP addresses associated with apparently infringing activity. They did not necessarily identify the individual who uploaded or downloaded the work.

That distinction is not a technical excuse added after the fact. It changes the inference a court can fairly draw. A provider may know that a connection has been associated with repeated infringement while not knowing which person acted or whether the same person will act again. A decision to continue serving the account may affect a group of lawful and unlawful users at once. The decision is therefore evidence about the provider's response, but it is not automatically evidence that the provider intended to help a particular infringement.

Cox's record made the problem concrete. MarkMonitor sent 163,148 notices over roughly two years. Cox said it warned an account after a second notice, escalated to interruptions, suspensions, or telephone warnings, and made termination possible after 13 notices. Its contract prohibited subscribers from using the connection to post, copy, transmit, or disseminate infringing material. Sony emphasized that Cox terminated only 32 subscribers for infringement and pointed to statements it said showed a preference for protecting revenue. Cox emphasized that its warnings and suspensions ended 98 percent of identified infringement.

Those figures cannot be placed on one scale and read as a complete answer. The notice count measures reports about connection-level activity. The termination count measures one kind of provider action. The 98 percent figure was Cox's litigation position about the effect of its interventions. Each may be relevant to a different argument, but none alone proves intent. A large notice record may show awareness. A limited termination record may support criticism of policy implementation. A high claimed cessation rate may support Cox's argument that it discouraged infringement. The merits question still asks what the provider intended its service to help accomplish.

The majority's framework supplies the next filter. Active inducement looks for specific conduct that encourages infringement—promotion, marketing, instructions, or comparable evidence of an affirmative objective. A tailored-service theory asks whether the service lacks substantial or commercially significant noninfringing uses. Cox's ordinary Internet access did not meet either description on the record before the Court. Sony did not show that Cox promoted access as a tool for copyright infringement, and Internet access remained useful for many purposes other than infringement.

This reasoning preserves the lesson of both Sony/Betamax and Grokster.