Your Apps Know Where You Were Last Night, and They’re Not Keeping It Secret

The millions of dots on the map trace highways, side streets and bike trails — each one following the path of an anonymous cellphone user. One path tracks someone from a home outside Newark to a nearby Planned Parenthood, remaining there for more than an hour. Another represents a person who travels with the mayor of New York during the day and returns to Long Island at night.
Read more: https://www.nytimes.com/interactive/2018/12/10/business/location-data-privacy-apps.html?source=Snapzu