The American Civil Liberties Union said that the Erie County Sheriff’s Office in the US state of New York used invasive cellphone tracking devices called Stingrays to spy on local residents without a search warrant.

WASHINGTON (Sputnik) — The Erie County Sheriff’s Office in the US state of New York used invasive cellphone tracking devices called Stingrays to spy on local residents without a search warrant, the American Civil Liberties Union (ACLU) said in a press release.

“The Sheriff’s Office used Stingrays at least 47 times between May 1, 2010, and October 3, 2014,” the release, issued on Tuesday, said. “It appears that the office only obtained a court order in only one of those 47 circumstances.”

The Stingray is a briefcase-sized surveillance device that allows the police to spy on mobile phones by mimicking cell phone towers, according to the ACLU.

“Stingrays allow the police to pinpoint a person’s location, collect the phone numbers that a person has been texting and calling and, in some configurations, intercept the contents of communications,” the ACLU explained.

The ACLU noted the Sheriff’s Office promised the US Federal Bureau of Investigation (FBI) “breathtaking secrecy” to keep information about Stingrays as hidden as possible.

In November 2014, the US Marshals Service was exposed for using aircraft-mounted devices that indiscriminately scooped data from cellphones.

In June 2013, National Security Agency (NSA) whistleblower Edward Snowden leaked classified information about the electronic mass surveillance programs conducted by the US government around the world, including eavesdropping on US citizens and foreign leaders.