Fascinating, but a big piece missing from the article is where this data came from. The linked article [1] is much more clear: "The data reviewed by The Times

Fascinating, but a big piece missing from the article is where this data came from. The linked article [1] is much more clear: "The data reviewed by The Times Opinion didn’t come from a telecom or giant tech company, nor did it come from a governmental surveillance operation. It originated from a location data company, one of dozens quietly collecting precise movements using software slipped onto mobile phone apps. You’ve probably never heard of most of the companies — and yet to anyone who has access to this data, your life is an open book. They can see the places you go every moment of the day, whom you meet with or spend the night with, where you pray, whether you visit a methadone clinic, a psychiatrist’s office or a massage parlor." [1] https://www.nytimes.com/interactive/2019/12/19/opinion/location-tracking-cell-phone.html https://www.nytimes.com/interactive/2019/12/19/opinion/locat...