PrivacyACLU: Cell phone tracking by police widespread

Published 4 April 2012

ACLU obtains information from over 200 law enforcement agencies; finds widespread police use of cell phone location tracking along with variance in legal standards, technology used


In August, 2011, thirty-five affiliates of the American Civil Liberties Union filed over 380 public records requests with state and local law enforcement agencies asking about their policies, procedures, and practices for tracking cell phones.

In return they received over 5,500 pages of statements of policy, memoranda, police requests to cell phone companies, sometimes in the form of a subpoena or warrant, and invoices and manuals from cell phone companies explaining the companies’ procedures and prices for providing the requested data.

After reviewing the documents provided by over 200 police agencies, the ACLU found that the overwhelming majority of law enforcement agencies responding engage in at least some cell phone tracking. Only ten police departments said that they had never tracked cell phones.

As long as a cell phone is powered on, it registers its location with the nearest cell tower several times per minute, and this function cannot be turned off. The result is minute-by-minute tracking of the general area where the cell phone is located.

The ACLU found that some police departments, citing Raleigh, North Carolina as an example, track hundreds of cell phones per year, based on invoices from cell phone carriers.

There is also a wide variance in the way the cell phone data is obtained. While some law enforcement agencies obtain warrants based on probable cause, most do not. Some use the less-strict standard of ” ‘relevant and material’ to an ongoing investigation.”

There is an equally wide range in the technology used, and the information requested. The ACLU cited the Lincoln, Nebraska police as the more precise GPS location data without demonstrating probable cause.

Most often, police request information on one cell phone number from a carrier. Occasionally, the request is for all the cell phone numbers in a particular area at a particular time, or all phones that utilized a particular cell tower.

Some law enforcement agencies have purchased their own cell phone tracking equipment. The Gilbert, Arizona Police department used $150,000 from a State Homeland Security Program grant, in addition to other funds, to purchase their own equipment.