Trademark infringement actions are often won or lost at the preliminary injunction stage. Although a plaintiff seeking a preliminary injunction must ordinarily show a likelihood of suffering irreparable harm, plaintiffs in trademark cases once they have shown a likelihood of success on their infringement claims have traditionally benefited from a presumption of irreparable harm.
Two relatively recent U.S. Supreme Court decisions have thrown the continued viability of this presumption into question. In eBay Inc. v. MercExchange LLC, 547 U.S. 388 (2006), the Supreme Court held that it was error to apply a “general rule” in patent cases that injunctions should issue once validity and infringement had been determined. Two years later, in Winter v. Natural Resources Defense Council Inc., 555 U.S. 7 (2008), the court held that a party seeking a preliminary injunction must show that irreparable harm is “likely,” not merely “possible.” Although many commentators claimed that eBay and Winter heralded the death of the presumption of irreparable harm in intellectual property cases generally, more than five years after eBay the impact on trademark cases remains murky.
