95% of people can be identified from information about just four interactions with mobile networks, researchers have claimed.
An international team led by researchers from the Massachusetts Institute of Technology found that data derived from mobile phone networks, using just the location of radio masts, could identify the vast majority of people from just four pieces of information.
Writing in Nature, researchers explained that a simply anonymized dataset does not contain name, home address, phone number or other obvious identifier.
Yet, if individual's patterns are unique enough, outside information can be used to link the data back to an individual, they added.
According to the Telegraph, the study examined data collected over 15 months from 1.5 million people, and found that "human mobility traces are highly unique".
The authors said that a list of potentially sensitive professional and personal information that could be inferred about an individual knowing only his mobility trace was published recently by the Electronic Frontier Foundation.
This included the movements of a competitor sales force, attendance of a particular church or an individual's presence in a motel or at an abortion clinic, they added.
According to the paper, the discovery has raised questions over the increasing use by businesses and government agencies of supposedly anonymous data.