Written by international and extraterritorial law scholars, the attached amicus brief was submitted in the U.S. v. Microsoft case. That case involves whether Congress, when it enacted the Stored Communications Act, intended to provide federal and local law enforcement authority to unilaterally seize the private email communications of foreign citizens stored abroad.
The amicus brief explains how the Charming Betsy canon and the law of extraterritoriality are part of a well-defined body of law the U.S. Supreme Court has developed for determining how American law applies abroad. These doctrines exist independently: one aims to avoid unsanctioned violations of international law. The other prevents the improper projection of American legal power beyond our borders. But they share much in common. Both rest on a properly restrained understanding of the judiciary’s place in our constitutional order, under which the often-delicate issues of foreign affairs in lawmaking are properly reserved to Congress, not courts. And both are grounded on shared insights the Court has gained over time about Congress’s approach to lawmaking: Its preference for “domestic, not foreign matters;" its respect for other nations’ sovereignty; its regard for international law; its inclination toward international collaboration; and perhaps most importantly of all, its avoidance of international friction and strife — unless some overriding policy need compels congressional action despite the risk of such strife.
The brief explains why the Court should preserve the assumptions about extraterritoriality that the legislative and judicial branches have shared since the Republic’s early days. These shared assumptions properly constrain law enforcement and other governmental actors. They also prevent the march of technological progress from introducing an extraterritorial creep into laws that Congress intended to remain domestically fixed. And they push the Executive to engage with Congress to address cross-border challenges, including transnational crime. It explains why the electronic seizure of electronic records physically located in another country is an exercise of extraterritorial enforcement jurisdiction in violation of international law, and why the Court's extraterritoriality jurisprudence prohibits assuming, when no indication exists in the statute, that Congress authorized borderless law enforcement.
Anthony J. Colangelo and Austen L. Parrish, International Law and Extraterritoriality: Brief of International and Extraterritorial Law Scholars as Amici Curiae (U.S. v. Microsoft) (January 18, 2018).