‘Data is a fingerprint’: why you aren’t as anonymous as you think online

So-called ‘anonymous’ data can be easily used to identify everything from our medical records to purchase histories. By analysing a mobile phone database of the approximate locations (based on the nearest cell tower) of 1.5 million people over 15 months (with no other identifying information) it was possible to uniquely identify 95% of the people with just four data points of places and times. About 50% could be identified from just two points.

Source: ‘Data is a fingerprint’: why you aren’t as anonymous as you think online | World news | The Guardian