The new Web economy relies on the collection of personal data on an ever-increasing scale. Information about our tastes, purchases, searches, browsing history, friendships and relationships, health history, genetics and more is shared with advertisers, marketers and researchers, raising a number of privacy issues. In this talk from the University of Washington, Vitaly Shmatikov, an associate professor of computer science at the University of Texas at Austin, considers several approaches to privacy-preserving data sharing and show that "anonymization," including popular methods based on k-anonymity and similar syntactic properties, fails to provide meaningful privacy guarantees. From the Series:CSE Colloquia - 2010