The United States Supreme Court recently ruled, in a unanimous decision, that a successful plaintiff in a patent lawsuit is not necessarily entitled to a permanent injunction.  Instead, the District Court must analyze the propriety of a permanent injunction under the standard four-factor injunction test comprising the following factors:

1. The existence of an irreparable injury;

2. Whether remedies available at law, such as monetary damages, are inadequate to compensate for that injury;

3. Whether the balance of hardships favors injunctive relief; and

4. Whether an injunction would serve the public interest.

In reaching this decision, the Court rejected precedent holding that the grant of an injunction is nearly automatic in cases where patent infringement is found.  See e.g. Richardson v. Suzuki Motor Co., 868 F.2d 1226, 1246-47 (Fed. Cir. 1989)("It is the general rule that an injunction will issue when infringement has been adjudged, absent a sound reason for denying it.").  However, the practical effect of the Court’s ruling is hotly debated by practitioners.

Chief Justice Roberts’ concurring opinion states that in exercising their equitable discretion under the eBay test, courts should be mindful that historically, injunctions have usually been granted where patent infringement is found.  Many commentators cite this concurrence in support of their belief that courts will still grant injunctions in most cases.

Others contend that injunctions will rarely be granted, particularly in cases of so called "patent trolls"—those who own patents and license them, but don’t produce or sell any goods themselves.  They argue that in such cases, monetary recovery will often be adequate to compensate the patent holder and thus under the Supreme Court’s test, an injunction would properly be denied.