Communications and personal information that are posted online are usually accessible to a vast number of people. Yet when personal data exist online, they may be searched, reproduced and mined by advertisers, merchants, service providers or even stalkers. Many users know what may happen to their information, while at the same time they act as though their data are private or intimate. They expect their privacy will not be infringed while they willingly share personal information with the world via social network sites, blogs, and in online communities.

Part I Approaches.- Introduction to Privacy Online.- Three Theories of Privacy: An Overview.- Negotiating Privacy Concerns and Social Capital Needs in a Social Media Environment.- Digital Crowding: Privacy, Self-Disclosure, and Technology.- Ethics, Privacy, and Self-Restraint in Social Networking.- The Social Web as a Shelter for Privacy and Authentic Living.- 15 Minutes of Privacy: Privacy, Sociality, and Publicity on Social Network Sites.- The Co-Evolution of Social Network Ties and Online Privacy Behavior.- Self-Protection of Online Privacy - A Behavioral Approach.- Online Self-Presentation: Balancing Privacy Concerns and Impression Construction on Social Networking Sites.- The Uses of Privacy Online: Trading a Loss of Privacy for Social Web Gratifications?.- (Micro)Blogs: Practices of Privacy Management.- Part II Applications.- Privacy in Social Network Sites.- Mobile Privacy: Contexts.- Online Privacy as a News Factor in Journalism.- Adolescents' Online Privacy Toward a Developmental Perspective.- The Elderly and the Internet: How Senior Citizens Deal with Online Privacy.- Privacy and Gender in Social Web.