A new study from researchers at MIT and Louvain University highlights how mobile phones have the capacity to be used as tracking devices. The study analyzed human mobility data for over 1.5 million people over fifteen months. The results were ominous for personal privacy. The study, published in Nature, found that 95% of mobile users can be uniquely identified by location data if their phone interacts with the carrier’s network at least once an hour.
What does it mean to “interact with the network”? Any time you send a message, make a call, receive an SMS your phone communicates with the nearest cell tower. The study was carried out from 2006 to 2007, before the current pervasiveness of smartphones with more accurate geolocation data and apps that use voluntary self-geotagging.
Dispatch uses mobile devices as the means of publication, partially because phones are so ubiquitous among both reporters and activists. This study highlights the need for users to begin their security measures at the most basic level: removing the battery when the device is not in use (if possible) and limiting the access that apps have to your geolocation.