quoting the linked page... [edit: note that what Justice Black says applies whether or not the person is in US custody. He's laying out a restriction on ANY act

quoting the linked page... [edit: note that what Justice Black says applies whether or not the person is in US custody. He's laying out a restriction on ANY action by the US government against a US citizen outside of the US... the restriction against the US government has nothing to do with her detention]: the Court held that American citizens outside of the territorial jurisdiction of the United States retain the protections guaranteed by the United States Constitution. Accordingly, the decision below granting Mrs. Covert’s habeas petition was affirmed. Black wrote: “[W]e reject the idea that when the United States acts against citizens abroad it can do so free of the Bill of Rights. The United States is entirely a creature of the Constitution. Its power and authority have no other source. It can only act in accordance with all the limitations imposed by the Constitution. When the Government reaches out to punish a citizen who is abroad, the shield which the Bill of Rights and other parts of the Constitution provide to protect his life and liberty should not be stripped away just because he happens to be in another land.”