The bounty hunter sent the number to his own contact, who would track the phone. The contact responded with a screenshot of Google Maps, containing a blue circle indicating the phone’s current location, approximate to a few hundred metres.

Nervously, I gave a bounty hunter a phone number. He had offered to geolocate a phone for me, using a shady, overlooked service intended not for the cops, but for private individuals and businesses. Armed with just the number and a few hundred dollars, he said he could find the current location of most phones in the United States.

Whereas it’s common knowledge that law enforcement agencies can track phones with a warrant to service providers, IMSI catchers, or until recently via other companies that sell location data such as one called Securus , at least one company, called Microbilt, is selling phone geolocation services with little oversight to a spread of different private industries, ranging from car salesmen and property managers to bail bondsmen and bounty hunters, according to sources familiar with the company’s products and company documents obtained by Motherboard. Compounding that already highly questionable business practice, this spying capability is also being resold to others on the black market who are not licensed by the company to use it, including me, seemingly without Microbilt’s knowledge.

The bounty hunter did this all without deploying a hacking tool or having any previous knowledge of the phone’s whereabouts. Instead, the tracking tool relies on real-time location data sold to bounty hunters that ultimately originated from the telcos themselves, including T-Mobile, AT&T, and Sprint, a Motherboard investigation has found. These surveillance capabilities are sometimes sold through word-of-mouth networks.

Queens, New York. More specifically, the screenshot showed a location in a particular neighborhood—just a couple of blocks from where the target was. The hunter had found the phone (the target gave their consent to Motherboard to be tracked via their T-Mobile phone.)

Motherboard’s investigation shows just how exposed mobile networks and the data they generate are, leaving them open to surveillance by ordinary citizens, stalkers, and criminals, and comes as media and policy makers are paying more attention than ever to how location and other sensitive data is collected and sold. The investigation also shows that a wide variety of companies can access cell phone location data, and that the information trickles down from cell phone providers to a wide array of smaller players, who don’t necessarily have the correct safeguards in place to protect that data.

“People are reselling to the wrong people,” the bail industry source who flagged the company to Motherboard said. Motherboard granted the source and others in this story anonymity to talk more candidly about a controversial surveillance capability.

Got a tip? You can contact Joseph Cox securely on Signal on +44 20 8133 5190, OTR chat on jfcox@jabber.ccc.de, or email joseph.cox@vice.com.

Your mobile phone is constantly communicating with nearby cell phone towers, so your telecom provider knows where to route calls and texts. From this, telecom companies also work out the phone’s approximate location based on its proximity to those towers.

Although many users may be unaware of the practice, telecom companies in the United States sell access to their customers’ location data to other companies, called location aggregators, who then sell it to specific clients and industries. Last year, one location aggregator called LocationSmart faced harsh criticism for selling data that ultimately ended up in the hands of Securus, a company which provided phone tracking to low level enforcement without requiring a warrant. LocationSmart also exposed the very data it was selling through a buggy website panel, meaning anyone could geolocate nearly any phone in the United States at a click of a mouse.

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