Al writes "Many people reveal way too much personal information on social networking sites — something that can easily lead to identity theft or unwanted attention from employers etc. Technology Review has a story about several cryptographic tools that can be used to hide your activity on Facebook, from both untrusted users and from Facebook itself. Urs Hengartner, an assistant professor of computer science at the University of Waterloo, developed a Firefox plugin that obfuscates anything marked with '@@' on Facebook and only reveals the correct information to trusted users who have the right keys. The sensitive data itself is even stored on an outside server so that even Facebook cannot access it. The piece mentions two other projects, NOYB and flybynight, that also aim to make personal information more secure on Facebook."