The Tacoma Police Department, in Washington state just south of Seattle, has for years been quietly using controversial surveillance equipment that can collect records of all cellphone calls, text messages and data transfers within a half-mile radius, according to local media.

The stingray surveillance system, deployed by the Tacoma Police Department since 2009, “tricks cellphones into thinking it’s a cell tower and draws in their information,” local news website The Olympian reported Wednesday.

The device is reportedly capable of indiscriminate data collection, which worries civil rights advocates.

The American Civil Liberties Union said it has identified at least 43 police departments in 18 states that use stingray equipment. The rights group said on its website that police use of such a device may violate the U.S. Constitution's Fourth Amendment, and with taxpayers’ money.

"The result is that police gather the electronic serial numbers and other information about phones, as well as the direction and strength of each phone's signal, allowing precise location tracking,” the ACLU said. “Stingrays can also gather information about people's communications, such as which phone numbers they call. Because we carry our cellphones with us virtually everywhere we go, stingrays can paint a precise picture of where we are and who we spend time with, including our location in a lover's house, in a psychologist's office or at a political protest."

Tacoma Police Department’s Assistant Police Chief Kathy McAlpine said that officers use stingrays only with permission from a judge, and that they do not collect data.

“It is used in felony-level crimes to locate suspects wanted for crimes such as homicide, rape, robbery, kidnapping, and narcotics trafficking,” she said.

The department said the device has been used nearly 200 times since June.

The Tacoma City Council approved buying an updated version of the equipment in March 2013 on the grounds that it would be used to find improvised explosive devices. McAlpine said they have never used stingrays to locate such a device.

Civil rights groups said they are concerned about the possibility of indiscriminate data collection, and worry that police could store the data of innocent citizens.

“They are essentially searching the homes of innocent Americans to find one phone used by one person,” said Christopher Soghoian, the principal technologist with the ACLU in Washington, D.C. “It’s like they’re kicking down the doors of 50 homes and searching 50 homes because they don’t know where the bad guy is.”

A similar controversy erupted in nearby Seattle last November, when alternative news website The Stranger reported that a new apparatus capable of geolocating and tracking the movement of any wireless device that passes it was quietly installed in a Seattle neighborhood.

The U.S. Supreme Court unanimously ruled in June that warrantless searches of cellphone data were illegal in most cases. It is unclear how the ruling would apply to such a device that is capable of indiscriminate data collection, but police say it is not used for that purpose.

With wire services