Last week, the Ninth Circuit held in United States v. Wilson, No. 18-50440, 2021 WL 4270847, that a law enforcement officer violated a criminal defendant's Fourth Amendment rights when he opened images attached to the defendant's emails without a warrant, even though the images had previously been flagged as child sexual abuse materials ("CSAM") by Google's automated CSAM-detection software. The court based its ruling on the private search exception to the Fourth Amendment, which permits law enforcement to conduct a warrantless search only to the extent the search was previously conducted by a private party. Because no individual at Google actually opened and viewed the images flagged as CSAM, the court held that law enforcement "exceeded the scope of the antecedent private search," thereby "exceed[ing] the limits of the private search exception." Op. at 20-21.
Because the Fourth Amendment applies only to searches conducted by the government, "a private party may conduct a search that would be unconstitutional if conducted by the government." Op. at 13. If the private party later provides the fruit of that search to the...
