The U.S. Supreme Court issued a ruling on March 1, 2006, limiting antitrust actions against intellectual property owners by rejecting a presumption that the owner of a copyright or patent possesses market power under the antitrust laws. The Washington Legal Foundation (WLF) filed a brief in the case on August 4, 2005, urging the Court to reject that presumption. In its brief, WLF argued that intellectual property has no inherent characteristics that justify shifting the burden of proof in antitrust cases onto the owners of that property. WLF noted that the Federal Circuit’s rule would encourage frivolous nuisance suits by rendering it much easier for a suit to survive a motion to dismiss, even where the patent or copyright owner possesses no market power whatsoever. WLF also argued that the rule would encourage defendants in patent infringement actions to bring antitrust counterclaims, thus bypassing the requirements of the patent misuse defense created by Congress.