547 U.S. 388 (2006)
eBay Inc. operates a popular Internet Web site that allows private sellers to list goods they wish to sell, either through an auction or at a fixed price.1 Petitioner Half.com, now a wholly owned subsidiary of eBay, operates a similar Web site.2 Respondent MercExchange, L.L.C., holds several patents, including a business method patent for an electronic market designed to facilitate the sale of goods between private individuals by establishing a central authority to promote trust among participants.3 See U.S. Patent No. 5,845,265.4 MercExchange sought to license its patent to eBay and Half.com, as it had previously done with other companies, but the parties failed to reach an agreement.5
MercExchange subsequently filed a patent infringement suit against eBay and Half.com in the United States District Court for the Eastern District of Virginia.6 A jury found that MercExchange's patent was valid, that eBay and Half.com had infringed that patent, and that an award of damages was appropriate.7 eBay and Half.com continue to challenge the validity of MercExchange's patent in proceedings pending before the United States Patent and Trademark Office.8
Following the jury verdict, the District Court denied MercExchange's motion for permanent injunctive relief, 275 F. Supp. 2d 695 (2003).9 The Court of Appeals for the Federal Circuit reversed, applying its general rule that courts will issue permanent injunctions against patent infringement absent exceptional circumstances, 401 F.3d 1323, 1339 (2005).10 The Supreme Court granted certiorari to determine the appropriateness of this general rule, 546 U.S. 1029 (2005).11
Whether a federal court considering whether to award permanent injunctive relief to a prevailing plaintiff applies the four-factor test historically employed by courts of equity when the dispute arises under the Patent Act?12
According to well-established principles of equity, a plaintiff seeking a permanent injunction must satisfy a four-factor test before a court may grant such relief.13 A plaintiff must demonstrate (1) that it has suffered an irreparable injury; (2) that remedies available at law, such as monetary damages, are inadequate to compensate for that injury; (3) that, considering the balance of hardships between the plaintiff and defendant, a remedy in equity is warranted; and (4) that the public interest would not be disserved by a permanent injunction.14 The decision to grant or deny permanent injunctive relief is an act of equitable discretion by the district court, reviewable on appeal for abuse of discretion.15 These principles apply with equal force to disputes arising under the Patent Act.16 Nothing in the Patent Act indicates that Congress intended a major departure from the long tradition of equity practice.17 The Patent Act expressly provides that injunctions may issue in accordance with the principles of equity under 35 U.S.C. § 283.18
Yes. The established facts demonstrate that MercExchange prevailed after a jury trial in the Eastern District of Virginia that found its patent valid, infringed by eBay and Half.com, and warranting damages.19 Yet both lower courts deviated from the four-factor test.20 The District Court denied injunctive relief after reciting the test but adopted a categorical approach based on MercExchange's willingness to license and lack of commercial activity in practicing the patents.21 The Federal Circuit reversed by applying its own general rule favoring injunctions. Neither approach comports with the equitable discretion required by the traditional test and 35 U.S.C. § 283.22 The Supreme Court vacated the judgment of the Court of Appeals and remanded for the District Court to apply the proper framework in the first instance.23
The facts establish that eBay operates a popular Internet Web site allowing private sellers to list goods for auction or fixed-price sale while Half.com operates a similar site as its wholly owned subsidiary.24 MercExchange holds U.S. Patent No. 5,845,265 for a business method facilitating sales between private individuals through a central trust authority.25 MercExchange had previously licensed the patent to other companies before negotiations with eBay and Half.com failed.26 After the failed licensing talks, MercExchange filed suit, secured a jury verdict on validity, infringement, and damages, and then moved for a permanent injunction that the District Court denied at 275 F. Supp. 2d 695.27
The Court of Appeals for the Federal Circuit reversed at 401 F.3d 1323 by invoking its general rule that permanent injunctions issue against patent infringement absent exceptional circumstances.28 The Supreme Court granted certiorari at 546 U.S. 1029 to review that rule.29 Application of the four-factor test to these facts shows that the District Court's categorical denial based on licensing willingness cannot stand.30 Some patent holders such as university researchers may prefer licensing yet still satisfy the irreparable-injury and inadequate-remedies factors.31 The Federal Circuit's categorical grant likewise fails because the Patent Act subjects the right to exclude to equitable principles rather than mandating automatic injunctions.32
The Supreme Court therefore holds only that injunctive relief decisions rest within district courts' equitable discretion exercised consistently with traditional principles, without taking a position on whether an injunction should issue in this case.33
Related opinions on this issue
Chief Justice Roberts agrees that the decision whether to grant or deny injunctive relief rests within district courts' equitable discretion exercised consistent with traditional principles of equity in patent disputes no less than in other cases.36 He emphasizes that the opinion rests on the proposition that a major departure from the long tradition of equity practice should not be lightly implied.37
From at least the early nineteenth century, courts granted injunctive relief upon a finding of infringement in the vast majority of patent cases. This practice stemmed from the difficulty of protecting a right to exclude through monetary remedies that allow an infringer to use an invention against the patentee's wishes.38
This historical practice does not entitle a patentee to a permanent injunction or justify a general rule that such injunctions should issue.39 At the same time there is a difference between exercising equitable discretion pursuant to the established four-factor test and writing on an entirely clean slate.40 Discretion is not whim, and limiting discretion according to legal standards helps promote the basic principle of justice that like cases should be decided alike.41
When it comes to discerning and applying those standards, a page of history is worth a volume of logic.42
Whether the Court of Appeals for the Federal Circuit properly applied a general rule that courts will issue permanent injunctions against patent infringement absent exceptional circumstances?43
The Court of Appeals for the Federal Circuit erred by articulating a general rule unique to patent disputes that a permanent injunction will issue once infringement and validity have been adjudged.44 Injunctions should be denied only in the unusual case under exceptional circumstances and in rare instances to protect the public interest.45 This categorical approach departs from the equitable discretion required by the traditional four-factor test and 35 U.S.C. § 283, just as the District Court's categorical denial departed in the opposite direction.46
No. The established facts show that, after the jury found MercExchange's patent valid and infringed by eBay and Half.com, the Federal Circuit reversed the District Court's denial of injunctive relief solely by applying its general rule that permanent injunctions issue absent exceptional circumstances.47 This rule improperly substitutes a near-automatic grant for the case-specific weighing of irreparable injury, adequacy of legal remedies, balance of hardships, and public interest that the Supreme Court requires.48 The Patent Act's provision that injunctions may issue in accordance with principles of equity precludes any such unique general rule for patent cases.49
The Federal Circuit's general rule favoring permanent injunctions in patent cases absent exceptional circumstances is rejected because it fails to apply the traditional four-factor equitable test to the facts of MercExchange's infringement suit against eBay and Half.com.50
Related opinions on this issue
Joined by Justice Stevens, Justice Souter, And Justice Breyer
Justice Kennedy concurs that courts should apply the well-established four-factor test without resort to categorical rules in deciding whether to grant injunctive relief in patent cases.51 He notes that the traditional practice of issuing injunctions against patent infringers illustrates the result of the four-factor test in the contexts then prevalent rather than resting on any inherent difficulty of monetary remedies.52
The lesson of the historical practice is most helpful when the circumstances of a case bear substantial parallels to litigation the courts have confronted before.53
In cases now arising the nature of the patent being enforced and the economic function of the patent holder present considerations quite unlike earlier cases.54 An industry has developed in which firms use patents not as a basis for producing and selling goods but primarily for obtaining licensing fees.55 For these firms an injunction can be employed as a bargaining tool to charge exorbitant fees.56
When the patented invention is but a small component of the product and the threat of an injunction is employed simply for undue leverage legal damages may well be sufficient.57 Injunctive relief may also have different consequences for the burgeoning number of patents over business methods whose potential vagueness and suspect validity may affect the calculus under the four-factor test.58 The equitable discretion granted by the Patent Act is well suited to allow courts to adapt to rapid technological and legal developments.59