Chatrie v. United States · ¶139

Three of those aspects—duration, comprehensiveness, and voluntariness—deserve mention here. First, unlike traditional police-surveillance techniques, the dataset in Carpenter captured the “whole of [a person’s] physical movements” over 127 days, violating Americans’ reasonable expectation that they would not be “secretly monitor[ed]” for a “very long period.” Id., at 310 (internal quotation marks omitted). Second, the dataset gave the police an “allencompassing record” of the defendant’s whereabouts that tracked him “beyond public thoroughfares and into private residences . . . and other potentially revealing locales.” Id., at 311. Third, the Court determined that cell-phone users do not “voluntarily” share their cell-site information with cellular carriers in the same way that the defendant in Mil ler voluntarily conveyed his transaction information to a bank. Carpenter, 585 U. S., at…

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