Design investigate a privacy protection system

Choose an existing or proposed privacey-enhancing system and rigorously analyze its strengths and/or weaknesses. Propose and implement a new tool for protecting privacy. Examples:

Develop an enforcement mechanism for enterprise privacy policies based on decentralized information flow control.

Study privacy aspects of some networked consumr device: for example, Kinect or Up by Jawbone.

Build a system for privacy-preserving Web browsing that would be secure against timing attacks.

Investigate a popular network protocol from a privacy perspective and design a new, privacy-preserving version.

Investigate algorithmic aspects (decidability, complexity, etc.) of some legally mandated privacy policy. For example, what does it take to enforce HIPAA for medical data or Gramm-Leach-Bliley for financial data?