Motherboard's source only had to pay a bounty hunter $300 to successfully find the location of a (willing accomplice's) phone, and the result was even accurate to within a third of a mile. That bounty hunter got their information from a company called Microbit, which gets information from Zumigo and offers location services to bail bond agents. In other words, carriers can't control where the data they sell goes, and it ends up trickling down to different industries, making it easy for anybody to purchase location information.
In response to the report, Senate Democrats are urging the FCC to investigate the practice and to put regulations that would compel carriers to be upfront about customers' data in place. "This is just another example that of how unwitting consumers are to the ways in which their data is collected, sold or shared, and commercialized," Senator Mark Warner told Motherboard. "It's not that people 'don't care about privacy,' as some have argued -- it's that customers, along with policymakers, have been kept in the dark for years about data collection and commercialization practices." Warner also said that federal agencies and the Congress should continue holding hearings to discuss and shed more light on the practice of buying and selling data.