Online social networks typically provide tools for users to set who can access their shared data. However, this access restriction only applies to network users and not for third parties and the social network itself. An approach only with data encryption is insufficient to keep both data privacy and the user's ability to obtain personalized services. This paper presents a model to extend the privacy in online social networks, ensuring the privacy of certain data from other network users, third parties and own social network, yet allowing the use of personalized services for users of social networking.