Ebay Inc. v. Mercexchange, L. L. C.
The Supreme Court ruled that courts cannot automatically issue a permanent injunction just because a patent has been found valid and infringed. Instead, judges must apply the same traditional four-factor balancing test used in other kinds of lawsuits before deciding whether to block an infringer from continuing to use the patented invention.
The decision struck down a Federal Circuit rule that treated injunctions as the default outcome in patent cases, giving trial judges more flexibility and making it harder for patent holders, especially companies that only license patents rather than make products, to automatically win a court order shutting down an alleged infringer.
“a major departure from the long tradition of equity practice should not be lightly implied”
The Court's reasoning for why patent injunctions should follow the same equitable rules as other cases.
How it got here: A jury found the patent valid and infringed; the trial court denied a permanent injunction, the Federal Circuit reversed under a rule favoring injunctions, and eBay asked the Supreme Court to review that rule.
The Case in Depth
What happened
eBay and its subsidiary Half.com run online marketplaces where people buy and sell goods. MercExchange held a patent on an electronic marketplace system designed to build trust between buyers and sellers by using a central authority. MercExchange tried to license the patent to eBay and Half.com, talks failed, and MercExchange sued for patent infringement. A jury found the patent valid and infringed and that damages were warranted.
The question before the Court
Should courts automatically grant a permanent injunction whenever a patent is found valid and infringed, or must they still weigh the traditional factors judges use before issuing any injunction?
Why it matters
Companies accused of patent infringement, especially technology firms, will no longer automatically face a shutdown order just because a jury finds infringement; judges can instead award money damages when that fits the situation better. Patent-licensing firms that don't make products themselves may find it harder to use the threat of an injunction as leverage to demand high licensing fees.
What changes now
The case goes back to the trial court, which must apply the traditional four-factor test to decide, on the facts of this specific dispute, whether MercExchange should get a permanent injunction against eBay and Half.com or instead be limited to money damages. The Supreme Court did not say which outcome is correct, so the injunction question remains open. eBay and Half.com were also separately challenging the patent's validity before the Patent and Trademark Office.
What this does not decide
The Court did not decide whether MercExchange should actually get an injunction against eBay and Half.com, or resolve how the four-factor test should come out in any other patent case. It only held that the traditional equitable test, not an automatic rule either way, governs the decision.
Concurrences and dissents
Concurrence — Justice Roberts
Chief Justice Roberts joined the majority in full but emphasized that a long history of courts granting injunctions once infringement is found should still guide how judges exercise their discretion under the four-factor test. He stressed that discretion should be applied consistently with legal standards, not as a blank slate, so that similar patent cases are decided alike.
Concurrence — Justice Kennedy
Justice Kennedy agreed with applying the four-factor test but pushed back on relying heavily on historical injunction practice, since older cases arose in different economic contexts. He warned that firms which only license patents for fees, rather than make products, might misuse the threat of an injunction as leverage, and that vague business-method patents may also affect how the test should apply.
How the Court got there
The legal reasoning, step by step
- The Court applied the traditional four-factor test long used by courts of equity before granting a permanent injunction: the plaintiff must show it suffered an irreparable injury, that money damages can't fix that injury, that the balance of hardships favors an injunction, and that an injunction wouldn't harm the public interest.
- The Court found nothing in the Patent Act signaling that Congress meant to abandon this traditional equitable approach for patent cases; the statute itself says injunctions 'may' issue only 'in accordance with the principles of equity,' which points toward applying the same four-factor test rather than a special patent-only rule.
- The Court reasoned that owning the legal right to exclude others from using an invention is a separate question from what remedy a court should give when that right is violated, so having a right to exclude doesn't by itself guarantee an injunction.
- Comparing patents to copyrights, the Court noted it had already rejected the idea that an injunction automatically follows a finding of copyright infringement, and treated patent injunctions the same way for consistency.
- The Court concluded that the trial court had gone too far by suggesting that patent holders who license their patents or don't make products themselves can never show irreparable harm, since some patent holders reasonably choose to license rather than manufacture.
- The Court also concluded that the Court of Appeals went too far in the opposite direction by treating an injunction as the near-automatic result of proving infringement, when equitable discretion requires case-by-case evaluation instead of a categorical rule.
Doctrinal impact
Cases affected by this decision
Reaffirms Continental Paper Bag Co. v. Eastern Paper Bag Co. (210 U. S. 405)
Relied on to reject the idea that a patent holder who doesn't use the patent can't get an injunction.