The growth of social networking sites has increased many threats to online users due to the increase in cyber-bullying and online crime rates through the use of social networking sites. The privacy settings and security are important and crucial to protect user privacy. To achieve online privacy, social network operators have devised several strategies to help protect user privacy while enjoying the services offered by the social network service providers. Today, social media users must be aware of the risks involved in virtual world. And users must learn how to protect themselves using privacy and security settings. This book will be beneficial to students, security specialists and other interested researchers who wish to understand the functionality behind social networking sites. We hope you will find the book useful and will enjoy reading it. We will be more than happy if we have motivated you so that you check the security settings of the social networks you use, especially of the Facebook in your future life.