Providing functionalities that allow online social network users to manage in a secure and private way the publication of their information and/or resources is a relevant and far from trivial topic that has been under scrutiny from various research communities. In this work, we provide a framework that allows users to define highly expressive access policies to their resources in a way that the enforcement does not require the intervention of a (trusted or not) third party. This is made possible by the deployment of a newly defined cryptographic primitives that provides - among other things - efficient access revocation and access policy privacy. Finally, we provide an implementation of our framework as a Facebook application, proving the feasibility of our approach.