I wrote a paper on privacy control in social networking sites. You can find the full paper at http://www.cse.hut.fi/en/publications/B/11/papers/li.pdf. Here’s the abstract:

As social networking services become increasingly popular, more and more attacks against users’ private information are reported. As a result, privacy protection becomes an important concern among users. Previous research has produced many different approaches to deal with privacy control in different social networking sites. In this paper, we make a survey on different approaches proposed to tackle the privacy issue in social networking sites. In particular, we put current approaches into three general categories, i.e. approaches addressing end users’ active participation, security automation based on machine learning algorithms, and privacy preserving by using a decentralized architecture for social networkingservices. Then we introduce and analyze some of the approaches in each category. Finally, we give some suggestions that may help privacy control in online social networks.