Your Apps Know Where You Were Last Night, and They’re Not Keeping It Secret - at least 75 companies have access | cross pond high tech | Scoop.it

Data reviewed by The Times shows over 235 million locations captured from more than 1.2 million unique devices during a three-day period in 2017.

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.

Yet another leaves a house in upstate New York at 7 a.m. and travels to a middle school 14 miles away, staying until late afternoon each school day. Only one person makes that trip: Lisa Magrin, a 46-year-old math teacher. Her smartphone goes with her.

An app on the device gathered her location information, which was then sold without her knowledge. It recorded her whereabouts as often as every two seconds, according to a database of more than a million phones in the New York area that was reviewed by The New York Times. While Ms. Magrin’s identity was not disclosed in those records, The Times was able to easily connect her to that dot.

The app tracked her as she went to a Weight Watchers meeting and to her dermatologist’s office for a minor procedure. It followed her hiking with her dog and staying at her ex-boyfriend’s home, information she found disturbing.

“It’s the thought of people finding out those intimate details that you don’t want people to know,” said Ms. Magrin, who allowed The Times to review her location data.

Like many consumers, Ms. Magrin knew that apps could track people’s movements. But as smartphones have become ubiquitous and technology more accurate, an industry of snooping on people’s daily habits has spread and grown more intrusive.

Lisa Magrin is the only person who travels regularly from her home to the school where she works. Her location was recorded more than 800 times there, often in her classroom .

A visit to a doctor’s office is also included. The data is so specific that The Times could determine how long she was there.

Ms. Magrin’s location data shows other often-visited locations, including the gym and Weight Watchers.

In about four months’ of data reviewed by The Times, her location was recorded over 8,600 times — on average, once every 21 minutes.