“Aggregating” or combining data from multiple sources can actually reveal surprisingly specific information. You might not work for the Pentagon, but your data can be aggregated in the same way to de-anonymize you. Here’s a small collection of these surprising privacy failures:
- The Classic Paper – Simple Demographics Often Identify People Uniquely shows that knowing just birth date, gender, and zip code is enough to uniquely identify most people.
- Netflix Debacle – An anonymous Netflix dataset was de-anonymized by correlating it with the IMDB database.
- Social Exposure – De-anonymizing social networks (by Arvind Narayanan) demonstrates how an anonymous Twitter graph can be re-identified using Flickr for auxiliary information.
- Your Words Betray You – Your choice of words in writing can be analyzed to uniquely identify you according to On the feasibility of Internet-Scale Author Identification.
- Location, Location, Location – The traces of your GPS location app, even your approximate location, is pretty unique. Outlined in Unique in the crowd, the privacy bounds of human mobility.
- Bitcoin is often thought of as an anonymous currency, but it’s surprisingly non-anonymous, considering its reputation. This is because a lot of information is contained in the public ledger that records all transactions. See also An analysis of Anonymity in the Bitcoin System.
Source: Tozny Blog