https://wccftech.com/spying-smartphones-near-white-house/

It appears someone has been spying on smartphones near the White House. While it remains unclear who was behind this surveillance campaign, a federal study has found signs of surveillance devices known as IMSI catchers or Stingray (by the brand name) in other sensitive locations in Washington, as well.

The details were made public earlier today when Senator Ron Wyden (D-OR) shared a letter (PDF) he received from the US Department of Homeland Security in May mentioning these surveillance devices that are used to spy on phone calls and text messages.