https://www.theverge.com/2019/1/8/18174024/att-sprint-t-mobile-scandal-phone-location-tracking-black-market-bounty-hunters-privacy-securus

On a December afternoon seven years ago, I showed up on the doorstep of Carrier IQ totally unannounced. The controversial company had been accused of providing AT&T, Sprint, and T-Mobile with the means to track users’ phones and log their personal data using a secret app that users couldn’t remove. (I was naïve enough to think that I’d crack that wide open just by showing up.)

At the time, Carrier IQ was a scandal that appeared to be getting resolved by device makers and OS vendors, thanks to pressure from Congress. But now, it seems, we take it for granted that cell carriers know where our phones are, and we merely expect that data to be kept private.