The Department of Homeland Security last year found evidence of devices that can secretly catch cell phone communications around the White House and other "potentially sensitive" areas of Washington, D.C., a letter made public Friday reveals.
Sen. Ron Wyden, D-Ore., said that the letter, written to him by Homeland Security official Christopher Krebs, is "more evidence" that Americans are "being spied on, tracked, or scammed," possibly by foreign spy agencies in some cases.
Wyden said phone companies and the Federal Communications Commission should be taking action to strengthen cell phone security on the heels of the letter.
Homeland Security said sensors it deployed from January 2017 through November spotted activity that appeared consistent with the devices, which can monitor individual cellphone calls and texts. Known formally as International Mobile Security Identity devices, they are commonly known as StingRays.
Such devices are known to be used by foreign spies.
But the department said it had not validated the findings or attributed them to "specific entities, devices or purposes."
And Homeland Security said the evidence of cell phone tracking it detected in some cases apparently resulted from "legitimate cell towers."
However, the findings were shared with "the appropriate Federal agencies," according to the letter from Krebs to Wyden.
The Washington Post on Friday noted that Homeland Security's findings support independent research that has concluded that foreign spies have used such technology to conduct surveillance on U.S. officials in D.C.
Wyden said in a prepared statement, "The news of a possible foreign stingray near the White House is of particular concern [given] reports that the President isn't even using a secure phone to protect his calls."
"The cavalier attitude toward our national security appears to be coming from the top down. It is high time for the FCC and this administration to act immediately to protect American national security."
Wyden also noted that the letter confirms that Homeland Security has reports indicating that "'nefarious actors may have exploited' a weakness in phone networks known as SS7, 'to target the communications of American citizens.'"