Chatrie v. United States · ¶28

The magistrate issued the warrant, and officers executed it in the manner prescribed. At the first stage of the process, Google gave up anonymized data for 19 users found within the geofence during the hour within which the robbery occurred. At the second stage, the officers winnowed the list to nine users. And Google produced anonymized data showing their movements both inside and outside the geofence for the extended two-hour period. At the third and last step, the police again narrowed the list, this time to three users. Google responded with their identifying information. One of the three was Chatrie. The location data showed that he entered the geofenced area about ten minutes before the robbery, and headed toward a residential area of town immediately after leaving the bank.

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