MGM Studios v. Grokster: The Inducement Rule and Its Limits

In MGM Studios v. Grokster, decided June 27, 2005, the Supreme Court ruled unanimously that a company distributing software can be sued for its users’ copyright infringement when the company actively promotes the software as a tool for that infringement. The decision created a new basis for secondary copyright liability, known as the inducement rule, without disturbing the older protection for technologies capable of substantial lawful use.

The Dispute Behind the Case

Grokster and StreamCast Networks distributed free peer-to-peer file-sharing software. Their networks let users’ computers connect directly to one another to swap files, with no central company server acting as an index. That design was a deliberate response to the Napster litigation, which had shut down an earlier service that relied on central servers. Grokster and StreamCast argued that because their software generated file indexes across randomly selected user computers, they had no control over what users shared.¹

What actually moved across the networks told a different story. A study commissioned by MGM found that nearly 90% of the files available on the FastTrack network used by Grokster were copyrighted works, with billions of files being shared each month.² Suing individual users at that scale was not realistic, so MGM and other copyright holders went after the distributors instead.

The Sony Betamax Problem

The defendants leaned on a 1984 Supreme Court decision, Sony Corp. of America v. Universal City Studios, Inc. There, the Court held that selling copying equipment “does not constitute contributory infringement if the product is widely used for legitimate, unobjectionable purposes, or, indeed, is merely capable of substantial noninfringing uses.”³ Because VCRs had lawful uses, Sony was not liable for how buyers used them.

The Ninth Circuit read Sony broadly and granted summary judgment for Grokster and StreamCast, reasoning that their software also had some lawful uses and that this alone shielded the distributors from liability. The Supreme Court took the case to decide whether that reading swept too far.

The Inducement Rule

Justice Souter’s opinion for a unanimous Court set out a new rule. “One who distributes a device with the object of promoting its use to infringe copyright, as shown by clear expression or other affirmative steps taken to foster infringement, going beyond mere distribution with knowledge of third-party action, is liable for the resulting acts of infringement by third parties using the device, regardless of the device’s lawful uses.”¹

Intent is the pivot. Merely knowing that some users will infringe does not create liability. Actively encouraging infringement, through marketing, product design choices, or business strategy, does. The Court drew the concept from patent law’s longstanding inducement doctrine and adapted it for copyright.

Sony survived. Its “substantial noninfringing uses” test still protects distributors who simply put a capable product into the market. Inducement operates as an independent path to liability that runs alongside Sony, so a product with legitimate uses can still expose its maker to a lawsuit if the maker actively pushed users toward illegal use. The Court said the rule “does nothing to compromise legitimate commerce or discourage innovation having a lawful promise.”¹

What Showed Intent to Induce

Three categories of evidence pointed the Court toward inducement.

Positioning as the Napster Replacement

Both companies worked to capture Napster’s user base as the legal noose tightened on that service. StreamCast built an OpenNap program compatible with Napster’s software so users could migrate easily. Internal communications spelled out the plan. One executive email read: “We have put this network in place so that when Napster pulls the plug on their free service … or if the Court orders them shut down prior to that … we will be positioned to capture the flood of their 32 million users that will be actively looking for an alternative.” The OpenNap program was engineered “to leverage Napster’s 50 million user base.”²

StreamCast drafted advertising that asked, “Napster Inc. has announced that it will soon begin charging you a fee. That’s if the courts don’t order it shut down first. What will you do to get around it?” Grokster ran its own OpenNap system and embedded digital codes in its website so that searches for “Napster” or “free filesharing” landed on the Grokster download page.¹

A Business Model That Rewarded Infringement

Both companies gave their software away and made money by selling advertising within the application. Ad revenue rose with the user base, and the user base depended on access to popular copyrighted music and movies. The financial logic ran in one direction: more infringing content meant more users, and more users meant more revenue.

No Effort to Curb Infringement

Neither company built filtering tools or took other steps to reduce infringement, despite receiving millions of notices from copyright holders. Grokster sent newsletters touting its software’s ability to reach popular copyrighted material.² The Court was careful to add that a failure to filter, on its own, would not create liability for a product capable of substantial lawful use. Combined with the marketing and the business model, however, the inaction reinforced the picture of intent.¹

Where the Justices Disagreed

All nine agreed on the inducement rule. They split on a question the majority chose not to answer: whether Grokster’s software actually cleared the Sony threshold in the first place.

Justice Ginsburg, joined by Chief Justice Rehnquist and Justice Kennedy, would have held that the evidence of lawful uses was thin and that summary judgment for the defendants was improper even without inducement. Her approach would require defendants to show concrete present lawful uses and a realistic prospect of more over time.⁴

Justice Breyer, joined by Justices Stevens and O’Connor, went the other way. He described Sony’s rule as “forward looking” and “strongly technology protecting,” and concluded that the roughly 10% of noninfringing material on the networks, along with foreseeable future lawful uses, was enough to satisfy the standard. Breyer warned against tightening Sony because its clarity lets developers “know, ex ante, that distribution of their product will not yield massive monetary liability.”⁴

Because the majority resolved the case on inducement alone, lower courts were left without fresh guidance on how much lawful use counts as “substantial” under Sony.

What Happened to Grokster and StreamCast

The Court vacated the Ninth Circuit’s judgment and sent the case back for trial. Grokster settled in November 2005, agreeing to pay $50 million to the music and film industries, accepting a permanent injunction against further infringement, and shutting down its software and network.⁵ StreamCast litigated on, lost on remand, and ceased operations.

How the Rule Has Held Up

The inducement rule has become the standard framework for evaluating secondary copyright liability in technology cases. It separates companies that build broadly useful products and tolerate some misuse from companies that build their businesses around infringement and advertise accordingly. Routine activities such as offering technical support or product updates do not, by themselves, create liability.¹

The Supreme Court sharpened that line in March 2026 in Cox Communications, Inc. v. Sony Music Entertainment. The Court held that an internet service provider could not be held contributorily liable simply for continuing to provide internet access while knowing some subscribers used it to pirate music. Contributory liability through inducement, the Court reaffirmed, requires “active encouragement of infringement through specific acts.” Knowing about infringement is not enough. Cox contractually prohibited infringing use and enforced a graduated system of warnings, suspensions, and terminations, which the Court found incompatible with a finding of inducement.⁶

For a technology company, the practical takeaway from Grokster and Cox is that intent controls. What a company says about its product, how it markets it, and whether it takes any steps to discourage infringement carry as much weight as what the product technically does.

1
Justia U.S. Supreme Court Center. MGM Studios, Inc. v. Grokster, Ltd.
2
Legal Information Institute. Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd.
3
Justia. Sony Corp. of America v. Universal City Studios, Inc.
4
Legal Information Institute. Metro-Goldwyn-Mayer Studios Inc. v. Grokster, Ltd. – Concurrence
5
Pinsent Masons. Grokster to Pay $50 Million and Get Legal
6
Supreme Court of the United States. Cox Communications, Inc. v. Sony Music Entertainment