At least as long as two years ago, federal agents in Northern California used a sophisticated technology known as Stingray to pinpoint the exact location of a target, but failed to tell the judges issuing the warrants the full capabilities of the tracking devices. The trouble was, the agents had only gotten judicial permission for what’s known as pen register surveillance, which allow officials to monitor the phone numbers called, not the location or conversation of the subject.
Internal emails from San Francisco prosecutors disclosed in an Arizona case last week brought to light the concerns of federal prosecutors and their negotiations with judges over disclosure standards.
Stingray devices, called WIT in the emails from Miranda Kane, chief of the criminal division in the San Francisco U.S. Attorneys office, mimic a cell tower and can be placed in a van and used to pinpoint the location of cell phones, smart phones or broadband Internet cards. A mobile phone sends signals ever seven to 15 seconds to cell towers whether you are no the phone or not. The Stingray tricks a phone into connecting to it.
Kane’s email urges prosecutors to be “consistent and forthright” with judges about the use of Stingray when seeking judicial approval for pen register devices.
“As some of you may be aware, our office has been working closely with the magistrate judges in an effort to address their collective concerns regarding whether a pen register is sufficient to authorize the use of law enforcement’s WIT technology,” she wrote. “It has recently come to my attention that many agents are still using WIT technology in the field although the pen register application does not make that explicit.”
Adding to the privacy problems for prosecutors, Stingrays are indiscriminate. They locate not only the suspect’s cell phone, but also obtain information from all devices on the same network in a given area and “send signals into the homes, bags or pockets of the suspect and third parties alike,” according to the ACLU papers filed in the Arizona criminal case, U. S. v. Daniel Rigmaiden.
The ACLU, along with the San Francisco Bay Guardian, filed a Freedom of Information Act suit in 2012 in San Francisco, to determine the extent of the use of the device and implications for privacy rights and constitutional rights against illegal searches.
Then Daniel Rigmaiden, in Arizona, sought to suppress government evidence recovered during a 2008 investigation of alleged multimillion-dollar tax fraud, using the names of dead people. The information was allegedly recovered using Stingray technology and Rigmaiden’s case is the first constitutional test of Stingray technology.
When the ACLU received Kane’s email about Stingray during the San Francisco FOIA lawsuit, they sent the information on to Rigmaiden’s Arizona case and filed an amicus brief describing Stingray.
U.S. District Judge David Campbell in Phoenix is currently considering Rigmaiden’s request to suppress evidence in the case, based on claims that use of Stingray violated his Fourth Amendment rights.
Cases: U.S. v. Rigmaiden, No. 08-cr-0814DGC
ACLU of Northern Calif. v. Dept. of Justice, 12-cv-4008MEJ