According to the Department of Justice Policy Guidance: Use of Cell-Site Simulator Technology (Sept. 2, 2015), a cell-site simulator “function[s] by transmitting as a cell-site tower” as a means of remotely acquiring the “identifying information from cellular devices,” though not, according to the Guidelines, “emails, texts, contact lists, images or any other data from the phone.” The government appears to closely guard any information it derives from the use of this device. In fact, it issued a memorandum agreement in 2013 stipulated to dismiss cases rather than disclose use of a cell-site simulator. As discussed below, the accuracy of the Guidelines with respect to the scope and type of data a cell-site simulator can cull were also called into question in a dissenting opinion by the chief judge of federal appeals court. To that end, in 2016, a Freedom of Information Act (FOIA) request showed that the Virginia State Police used a cell-site simulator to capture not only GPS location and metadata, but also voice communication.
Proponents of cell-site simulators argue that the devices can, among other uses, investigate crimes, apprehend suspects, rescue crime victims, and assist citizens in distress. Many are unconvinced that these uses outweigh alleged privacy concerns. The optimism about cell-site simulators is not universally shared. For instance, the American Civil Liberties Union and its at state affiliates have sued state and federal governmental entities for information on how each are deploying cell-site simulators. Likely in partial response to these questions and the budding controversy, the U.S. Department of Justice (DOJ) announced in September 2015 that it would ordinarily seek a warrant, plus an order under the federal pen-register statute, 18 U.S.C §3123, prior to employing a cell-site simulator. At the same time, the DOJ has not conceded this is a constitutionally required protocol and the Guidelines are not binding upon state law enforcement officials.
