The Defense Intelligence Agency, which provides military intelligence to the Department of Defense, confirmed in a memo that it purchases "commercially available" smartphone location data to gather information that would otherwise require use of a search warrant.
The DIA "currently provides funding to another agency that purchases commercially available geolocation metadata aggregated from smartphones," the agency wrote in a memo (PDF) to Sen. Ron Wyden (D-Ore.), first obtained by the New York Times.
The Supreme Court held in its 2018 Carpenter v. United States ruling that the government needs an actual search warrant to collect an individual's cell-site location data. "When the Government tracks the location of a cell phone it achieves near perfect surveillance, as if it had attached an ankle monitor to the phone’s user," Chief Justice John Roberts wrote for the majority in his opinion. "The retrospective quality of the data here gives police access to a category of information otherwise unknowable."