They look like a retro stereo receiver or a synthesizer without keys. They’re about the size of a suitcase. And they can eavesdrop on phone calls and intercept messages.

They’re called cell-site simulators, or “Stingrays.”

For the first time, the government has --- sort of --- admitted they exist. According to the Associated Press, “foreign spies and criminals could be using [them] to track individual cellphones and intercept calls and messages” in Washington, DC, the home of the CIA, FBI, NSA and other security organizations. And, a lot of the agents and operatives of those agencies, with cellphones full of sensitive information, live in the DC area.

In the wrong hands, Stingrays can be used for more nefarious purposes

Stingrays are fairly common. Many police departments use them to determine the exact location of a cellphone. In the wrong hands, Stingrays can be used for more nefarious purposes, like spreading malware.

In November, Senator Ron Wyden wrote a letter to the Department of Homeland Security, requesting information about the possibility of cell-site simulators in the DC area.

In response, Department of Homeland Security official Christopher Krebs wrote a letter, which leaked yesterday, that “malicious actors” have been using the devices to unlawfully “track and monitor cellphone users.” Krebs added that surveillance equipment “threatens the security of communications, resulting in safety, economic, and privacy risks.”

Beyond that, the letter was vague. No mention of the who, what or why. No mention of how many or how much.

The DHS has conducted a series of examinations, but the details are hazy at best. Contractors and phone companies have had a role in the investigations.

In response to the letter, Senator Wyden said that “leaving security to the phone companies has proven to be disastrous.”