[2] Following the verdict, MercExchange sought an injunction to prevent eBay's continued use of its intellectual property, but the District Court denied the request.

Although the District Court recited the traditional four-factor test, 275 F.Supp.2d, at 711, it appeared to adopt certain expansive principles suggesting that injunctive relief could not issue in a broad swath of cases.

Such patent holders may be able to satisfy the traditional four-factor test, and we see no basis for categorically denying them the opportunity to do so.The court noted that it had consistently rejected invitations to replace traditional equitable considerations with a rule allowing automatic injunctions in its copyright law cases such as New York Times Co. v. Tasini, 533 U.S. 483 (2001).

On the other hand, Justice Kennedy, joined by Justices Stevens, Souter, and Breyer, wrote in a separate concurring opinion: In cases now arising trial courts should bear in mind that in many instances the nature of the patent being enforced and the economic function of the patent holder present considerations quite unlike earlier cases.

An industry has developed in which firms use patents not as a basis for producing and selling goods but, instead, primarily for obtaining licensing fees.

... For these firms, an injunction, and the potentially serious sanctions arising from its violation, can be employed as a bargaining tool to charge exorbitant fees to companies that seek to buy licenses to practice the patent.

In addition injunctive relief may have different consequences for the burgeoning number of patents over business methods, which were not of much economic and legal significance in earlier times.