This week, the Department of Justice issued an important “enhanced policy for use of cell-site simulators” (also known as stingrays, triggerfish, or IMSI catchers). The document essentially admits what many have criticized about the devices—that they “force every cell phone in a region to connect to them; so if a government stingray drives past your office, it will collect the signal of your phone as well as the government’s target.” In the DOJ’s words: “When used to locate a known cellular device, a cell-site simulator initially receives the unique identifying number from multiple devices in the vicinity of the simulator. Once the cell-site simulator identifies the specific cellular device for which it is looking, it will obtain the signaling information relating only to that particular phone. When used to identify an unknown device, the cell-site simulator obtains signaling information from non-target devices in the target’s vicinity for the limited purpose of distinguishing the target device” (emphasis added).
Before the new policy, police routinely disguised use of stingrays by using them under the auspices of a “pen register” order. But scholars argue that these devices are capable of much more than pen registers, which are devices that merely record “numbers called from a particular telephone line.”
Under the enhanced guidelines, agents are instructed to obtain a search warrant before using a stingray. On top of that, the search-warrant applications are to disclose certain information about the technology. This includes notifying the judge that the devices can sweep up “unique identifiers” from non-targeted phones and disrupt service to those phones.
The policy further instructs that “cell-site simulators used by the Department must be configured as pen registers, and may not be used to collect the contents of any communication, in accordance with 18 U.S.C. § 3127(3).”
Time will tell if this enhanced policy will move the needle on the secretive nature of these devices. As EFF notes, “[u]ntil recently, law enforcement’s use of Stingrays has been shrouded in an inexplicable and indefensible level of secrecy.”