United States v. Davis

Brief of Amici Curiae of the American Civil Liberties Union Foundation, American Civil Liberties Union Foundation of Florida, Inc., Center for Democracy & Technology, Electronic Frontier Foundation, and National Association of Criminal Defense Lawyers.

Brief filed: 07/17/2013


United States v. Davis

11th Circuit Court of Appeals; Case No. 12-12928


Warrantless acquisition of long-term historical cell site location information violated defendant’s reasonable expectation of privacy under the Fourth Amendment. Defendants’ cell site location information obtained by the government reveals invasive and accurate information about their location and movements over time. Obtaining 67  days’ worth of cell phone location data is a “search” under the Fourth Amendment requiring a warrant based upon probable cause. Cell phone providers’ ability to access customers’ location data does not eliminate cell phone users’ reasonable expectation of privacy in that data. Even if the good faith exception applies, this court should decide the Fourth Amendment question.

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Catherine Crump, Ben Wizner, and Nathan Freed Wessler (admission pending), ACLU Foundation, New York, NY.