The document introduces the Tracking Protection Working Group (TPWG) at the World Wide Web Consortium (W3C). It summarizes the TPWG's goal of developing standards around a "Do Not Track" browser header to express user preference not to be tracked online. It outlines the co-chairs and process for writing three standards documents. It also discusses some of the major issues still to be resolved, including how to define first, second, and third parties as well as permitted third party uses.