The Defense Intelligence Agency focuses on foreign threats, but has searched for movements of American citizens at least five times over the past two and a half years, using cell phone data collected and sold by commercial brokers, according to an unclassified memo sent this week to Senator Ron Wyden (D-Oregon).

That specific time frame is due to the US Supreme Court decision in Carpenter v. United States, dated June 2018, which held that the government must obtain a warrant to get location data on cell phone users. However, the DIA “does not construe the Carpenter decision to require a judicial warrant endorsing purchase or use of commercially available data for intelligence purposes,” the New York Times reported on Friday, citing the memo to Wyden.

Makers of many smartphone apps can and do log the users’ locations, which are often sold to brokers – and they, in turn, resell it to advertisers as well as law enforcement and spies, apparently.

In what is perhaps the most famous example yet, Vice reported in November that US Special Operations Command (USSOCOM) had used cutouts to buy data on users of MuslimPro, a prayer schedule app downloaded by some 100 million people.

DIA did not identify which broker it was buying the data from, saying only that they sold bulk records that did not separate Americans from foreigners. Instead, the military spies filter the records for those that “appear to be” on US soil and place them in a separate database, the Wyden memo revealed. That database can be accessed only with special approval, and has so far been granted five times for “authorized purposes.”

The memo came in response to a query sent by Chris Soghoian, Wyden’s privacy and cybersecurity aide who previously worked at the American Civil Liberties Union (ACLU) as the chief technologist.

Wyden is interested in the subject because he has proposed additional safeguards on privacy of Americans, which the Oregon senator hopes will be included in the upcoming legislation reviving several provisions of the expired PATRIOT Act.

The previous attempt to do so stalled in the divided Congress due in part to objections from President Donald Trump, who cited the abuse of FISA warrants to spy on his campaign to demand changes – which neither Democrats nor his own Republicans were willing to make. Democrats now have the slim majority in both the House and the Senate, as well as the presidency.