Crook v. United States of America

On January 21, 2026, the U.S. Supreme Court decided Crook v. United States, a landmark case challenging the National Security Agency’s “Sentinel” program. The program used advanced AI to scan domestic and international electronic communications in bulk without individualized warrants, aiming to detect terrorist threats. John Crook, a journalist and privacy advocate, discovered his encrypted emails had been flagged and retained by the system. He sued, arguing the warrantless AI-driven analysis constituted an unreasonable search under the Fourth Amendment. The government claimed the AI merely processed metadata and that no human reviewed the content without probable cause. The Court examined whether algorithmic scrutiny of private communications equates to a search, and whether the third-party doctrine applies to machine learning models trained on personal data.

In a 6-3 decision, the Supreme Court held that the Sentinel program’s AI-driven content analysis qualifies as a search requiring a warrant based on probable cause. The Court reasoned that automated algorithmic scrutiny intrudes upon a reasonable expectation of privacy, and the scale of bulk collection exacerbates the intrusion. The program was declared unconstitutional, and the government was ordered to delete unlawfully obtained data.

Whether the warrantless use of artificial intelligence to scan and analyze the content of private communications constitutes a “search” under the Fourth Amendment, and whether the bulk collection program violates individuals’ reasonable expectation of privacy.

The ruling significantly curtailed the government’s ability to deploy AI for mass surveillance without judicial oversight. It spurred congressional debates on updating the Foreign Intelligence Surveillance Act and inspired similar privacy challenges globally. Civil liberties groups hailed the decision as a victory for digital privacy, while national security agencies warned of intelligence gaps. Tech companies faced renewed pressure to design encryption standards resilient against both unauthorized access and overbroad government scanning.