eBay Inc. v. MercExchange, L.L.C., 547 U.S. 388 (2006), is a case in which the Supreme Court of the United States unanimously determined that an injunction should not be automatically issued based on a finding of patent infringement, but also that an injunction should not be denied simply on the basis that the plaintiff does not practice the patented invention. Instead, a federal court must still weigh what the Court described as the four-factor test traditionally used to determine if an injunction should issue.