Anonymized Location Data: an Oxymoron?

May 13, 2020

Location data. To many the term sounds innocuous, boring really. Perhaps that is why society has allowed apps to collect and sell it with no significant regulation. An engaging (and well-illustrated) piece from Norway’s NRK News, “Revealed by Mobile,” shares the minute details journalists were able to put together about one citizen from location data purchased on the open market. Graciously, this man allowed the findings to published as a cautionary tale. We suggest you read the article for yourself to absorb the chilling reality. (The link we share above runs through Google Translate.)

Vendors of location data would have us believe the information is completely anonymized and cannot be tied to the individuals who generated it. It is only good for general uses like statistics and regional marketing, they assert. Intending to put that claim to the test, NRK purchased a batch of Norwegian location data from the British firm Tamoco. Their investigation shows anonymization is an empty promise. Though the data is stripped of directly identifying information, buyers are a few Internet searches away from correlating location patterns with individuals. Journalists Trude Furuly, Henrik Lied, and Martin Gundersen tell us:

“All modern mobile phones have a GPS receiver, which with the help of satellite can track the exact position of the phone with only a few meters distance. The position data NRK acquired consisted of a table with four hundred million map coordinates from mobiles in Norway. …

“All the coordinates were linked to a date, time, and specific mobile. Thus, the coordinates showed exactly where a mobile or tablet had been at a particular time. NRK coordinated the mobile positions with a map of Norway. Each position was marked on the map as an orange dot. If a mobile was in a location repeatedly and for a long time, the points formed larger clusters. Would it be possible for us to find the identity of a mobile owner by seeing where the phone had been, in combination with some simple web searches? We selected a random mobile from the dataset.

“NRK searched the address where the mobile had left many points about the nights. The search revealed that a man and a woman lived in the house. Then we searched their Facebook profiles. There were several pictures of the two smiling together. It seemed like they were boyfriend and girlfriend. The man’s Facebook profile stated that he worked in a logistics company. When we searched the company in question, we discovered that it was in the same place as the person used to drive in the morning. Thus, we had managed to trace the person who owned the cell phone, even though the data according to Tamoco should have been anonymized.”

The journalists went on to put together a detailed record of that man’s movements over several months. It turns out they knew more about his trip to the zoo, for example, than he recalled himself. When they revealed their findings to their subject, he was shocked and immediately began deleting non-essential apps from his phone. Read the article; you may find yourself doing the same.

Cynthia Murrell, May 12, 2020


One Response to “Anonymized Location Data: an Oxymoron?”

  1. Vineet Srivastav on May 14th, 2020 1:29 am

    I love this type of content, i really appreciate this.

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