Sosa v. Alvarez-Machain, 542 U.S. 692 (2004), was a United States Supreme Court case involving the Alien Tort Statute and the Federal Tort Claims Act. Many ATS claims were filed after the Second Circuit ruling in Filártiga v. Peña-Irala created a new common law cause of action for torture under the ATS: “For purposes of civil liability, the torturer has become—like the pirate and slave trader before him—hostis humani generis, an enemy of all mankind.” The Court in Sosa does not find there is a similar cause of action for arbitrary arrest and detention. They wrote that finding new common law causes of action based on international norms would require "a substantial element of discretionary judgment", and explain that the role of common law has changed since ATS was enacted meaning the Court will "look for legislative guidance before exercising innovative authority over substantive law".The decision states some limitations on recognizing (or creating...