The Government Buys Your Movements Instead of Getting a Warrant
Anonymized phone data gives away its owner once you see where it sleeps and works.
The Shawn Ryan Show · #340 Byron Tau - The Government Doesn't Just Spy on You. It Buys You.The federal government does not need to track your phone to know where you have been. It can simply buy that history from companies that already collected it.
The trade began with property records and lists of who subscribed to magazines about pets, cooking, or guns. As people put more of their lives online, brokers added browsing history, precise movement through the world, and a way to link social media profiles to real identities.
Much of the movement data starts in ordinary apps, including weather apps and games. When a user agrees to share location, the app records the phone under an anonymized identifier, which ProPublica reporter Byron Tau, the author of Means of Control, described as "a string of letters and numbers," with no name or phone number attached.
That anonymity does not last. Tau explains that the phone that sleeps in one house at night and travels to one downtown office by day is a good clue to who owns it. He uses himself as the example: he is the only person who leaves his home in Washington, D.C., for his downtown office and returns each night.
That shortcut matters because of how American search law works. To get a month of movements from a phone company like AT&T, the government needs a warrant. To buy the same movements after a weather app has collected and sold them, it does not, because the purchase is treated as an ordinary commercial transaction and the Fourth Amendment, the Constitution's limit on government searches, does not apply.
Tau first heard about the practice at a dinner party about six years ago, when someone described a Defense Department program buying bulk phone movements for counterterrorism work. By 2020, the Department of Homeland Security was using commercial location data to track unlawful border crossings, find immigrants living in the country without authorization, and investigate ordinary crimes such as kidnappings, all without a judge approving a warrant and without most Americans knowing the programs existed.
Questions people ask
Why does buying data avoid the warrant requirement?
The Fourth Amendment limits government searches, not private collection. Under the third-party doctrine, courts have long held that information you voluntarily share with a business gets less protection, so buying it is treated more like shopping than searching.
Has the Supreme Court addressed phone location tracking?
Partly. In Carpenter v. United States in 2018, the Supreme Court ruled police generally need a warrant for historical cell-site records from carriers. The decision did not settle whether that rule applies when the same location history is bought from app-based brokers.
Does turning off location sharing keep my movements out of these datasets?
It helps but does not end collection. Many apps still infer location from Wi-Fi, purchases, or IP addresses, and phone makers now prompt users far more often to cut off background tracking. Denying location permission and deleting unused apps reduces the supply, but does not erase past records.