Whether the property-based approach to the Fourth Amendment applies to the government's warrantless search of email attachments compelled from a private party

QUESTION PRESENTED Applying the Fourth Amendment’s test, this Court has held that when a private actor searches someone’s property, the Government can then do it too. See United States v. Jacobsen, 466 U.S. 109 (1984). The Court reasoned that the private actor’s earlier intrusion means the Government “infringe[s] no legitimate expectation of privacy” by taking its own look. Id. at 120. That approach is one way to determine if a “search” has occurred. It was “added to, not substituted for, the traditional property-based understanding of the Fourth Amendment.” Florida v. Jardines, 569 U.S. 1, 5 (2013) (emphasis in original) (quoting United States v. Jones, 565 U.S. 400, 406 (2012)). Under the property-based approach, a search “has undoubtedly occurred” if “the Government obtains information by physically intruding on persons, houses, papers, or effects.” Id. Here, Google ran a proprietary algorithm that flagged possible contraband in petitioner’s Gmail account. Under federal law, Google was compelled to send petitioner’s private correspondence for examination by the Government. Upon receiving the files compelled from petitioner’s private email account, law enforcement opened them without a warrant. The question is: Whether Jacobsen’s conclusion “does not permit” courts to consider the traditional property approach, Pet. App. 35a, or whether the property-based approach applies and the government “conducted a ‘search’ when it opened and examined” petitioner’s email attachments, United States v. Ackerman, 831 F.3d 1292, 1308 (10th Cir. 2016). (i)