Way back in the callow, innocent days of, um, February 2013, the U.S. Supreme Court delivered its opinion in Clapper v. Amnesty International. The case stemmed from a challenge of the constitutionality of Section 702 of the Foreign Intelligence Surveillance Act of 1978, 50 U. S. C. §1881a.
If you didn’t pay much attention to the Court’s decision in Clapper back then, you might want to revisit it now that we know we’re all subject to NSA surveillance . . . .