If you want to follow someone in realtime, you don't need to shell out to shady data-brokers like Securus (which use a marketing company that exploits a privacy law loophole to obtain phone location data); there are a whole constellation of location data resellers who will do business with anyone, regardless of the notional privacy protections they promise the carriers they'll put in place.
Notably, these resellers do business with bail bondsmen and bounty hunters, who can, for a few dollars, locate any phone on the major carriers' networks.
The carriers were mired in scandal over the Securus affair last year, and pledged to clean up their act (T-Mobile CEO John Legere tweeted "I've personally evaluated this issue & have pledged that @tmobile will not sell customer location data to shady middlemen"). They have not.
Carriers contacted about this story said virtually the same thing they said last time.
Microbilt buys access to location data from an aggregator called Zumigo and then sells it to a dizzying number of sectors, including landlords to scope out potential renters; motor vehicle salesmen, and others who are conducting credit checks. Armed with just a phone number, Microbilt's "Mobile Device Verify" product can return a target's full name and address, geolocate a phone in an individual instance, or operate as a continuous tracking service.
"You can set up monitoring with control over the weeks, days and even hours that location on a device is checked as well as the start and end dates of monitoring," a company brochure Motherboard found online reads.
Posing as a potential customer, Motherboard explicitly asked a Microbilt customer support staffer whether the company offered phone geolocation for bail bondsmen. Shortly after, another staffer emailed with a price list—locating a phone can cost as little as $4.95 each if searching for a low number of devices. That price gets even cheaper as the customer buys the capability to track more phones. Getting real-time updates on a phone's location can cost around $12.95.
"Dirt cheap when you think about the data you can get," the source familiar with the industry added.
I Gave a Bounty Hunter $300. Then He Located Our Phone [Joseph Cox/Motherboard]