> To make sure his phone wasn’t keeping a record of everywhere he’d been — and potentially transmitting it to apps he was using — he turned off all its geolocation services.
... Of course, IMEI tracking (from tower registration) can get you pretty much all of this data anyway. This article is more about how to partially obfuscate your identity to private actors.
It would be interesting to know how fast a professional could unravel all of this. Minutes? Hours?