Social networking websites are enormously popular, but they present a number of privacy risks to their users, one of the foremost of which being that social network service providers are able to observe and accumulate the information that users transmit through the network. We aim to mitigate this risk by presenting a new architecture for protecting information published through the social networking website, Facebook, through encryption. Our architecture makes a trade-off between security and usability in the interests of minimally affecting users' workflow and maintaining universal accessibility. While active attacks by Facebook could compromise users' privacy, our architecture dramatically raises the cost of such potential compromises and, importantly, places them within a framework for legal privacy protection because they would violate a user's reasonable expectation of privacy. We have built a prototype Facebook application implementing our architecture, addressing some of the limitations of the Facebook platform through proxy cryptography.