It's a surveillance tool that allows law enforcement agencies to simulate a cellphone tower that lets them track a suspect's phone and their movement.
But the technology also captures information from other phone users in the area.
That, says the American Civil Liberties Union of California, raises serious concerns about the privacy issues surrounding the device known as a StingRay. The ACLU is suing the Anaheim Police Department and Sacramento County Sheriff's Department for failing to turn over documents to the organization demonstrating their use of that or similar devices.
Last summer ACLU attorneys filed requests for those documents under the California Public Records Act.
In two lawsuits filed Tuesday, the ACLU describe the StingRay as operating in "a sweeping dragnet manner"; it is not only able to capture the identity of the phone user but also the content of calls and messages, according to the lawsuits.
"StingRays are capable of invading the privacy of innocent Americans, so the public must be able to monitor how law enforcement agencies use them," said Peter Bibring, director of police practices for the ACLU of California. "The police cannot adopt a new, invasive surveillance technology without any kind of public oversight or accountability."
Calls to Anaheim police for comment were not returned. Sacramento sheriff's Sgt. Lisa Bowman said the department would not comment on pending litigation.
The device has been used in one form or another since the 1990s. The secrecy around how it's used and what exactly it captures has led to litigation across the country by organizations and individuals seeking to learn more about it.
In prior cases, federal authorities have insisted that though the technology connects with phones, it is not used to gather calls or texts. Officials argued that law enforcement agencies don't need a search warrant to use devices like the StingRay.
As many as four dozen federal and local agencies have acknowledged using the devices, according to prior litigation and public records. The small, suitcase-sized device acts like a miniature cellphone tower and sends out a signal that tricks the cellphone into transmitting back its identity and data.
In this case, the ACLU requested records from the two sued law enforcement agencies including any contracts or agreements with the Florida-based manufacturer of StingRays--Harris Corp., any judicial authorizations for the use of the StingRay, data-sharing policies and funding requests.
According to the suit, the Sacramento sheriff's office initially denied access to documents before providing five redacted documents. The department cited the Homeland Security Act and the Arms Export Control Act as reasons for withholding other records.
In Anaheim, the Police Department refused to produce those records, citing, among other things, the trade-secret privilege as support for its position that the documents requested by the ACLU are exempt from disclosure, according to the suit.
"We are not only trying to determine who is using them, but what policies govern those uses and what type of crimes it is being used to pursue," Bibring said.
The company that manufactures the device requires that the law enforcement departments using them sign a nondisclosure agreement, according to records. Bibring said the Los Angeles Police Department also has not turned over records of its use of the device to the ACLU.
But in 2006, documents first obtained by the LA Weekly revealed the LAPD had at least two of the devices at the time. In 2010, the department got the City Council to approve the purchase of a $347,000 StingRay using police foundation funds.
The Los Angeles County Sheriff's Department turned over records to the ACLU showing that it possesses the StingRay device. A 2011 asset forfeiture funds note that was heavily redacted said that the "equipment's capabilities are not for public knowledge and are protected under non-disclosure agreements" and federal law.
A sheriff's memo from 2009 noted that the equipment was to be acquired for use by its homicide bureau.
In Florida, which has among the most open government disclosure requirements, public records obtained by the ACLU showed that the state spent more than $3 million on the devices and related equipment. The Tallahassee police detailed 250 investigations in which it had used StingRays.
The California First Amendment Coalition has filed a lawsuit similar to the ACLU's against the San Diego police.
"The police cannot claim secrecy over their routine use of StingRays, invasive surveillance devices that indiscriminately collect data on suspects and bystanders alike," said Matt Cagle, an attorney with the ACLU in Northern California.