By Charles Choi

Anonymized credit card data can easily be used to identify credit card users, more evidence that anonymizing data does not protect privacy as well as often thought, scientists now find.

Personal information often gets anonymized by stripping it of names, home addresses, phone numbers and other obvious identifying details. Such data often get shared, and underlie popular services such as Google’s real-time traffic monitoring, which shows conditions on major thoroughfares in more than 50 different countries.

However, anonymized data can still reveal a great deal about individuals. For example, computational social scientist Yves-Alexandre de Montjoye at MIT and his colleagues recently found that anonymized cell phone data could be better at identifying users than fingerprints. At most, 11 randomly chosen interactions with cell phone networks were needed to identify a person by the routes he or she regularly traveled, while identifying someone by a fingerprint requires at least 12 reference points.  …[Read more]