Privacy is a basic human need, and losing privacy is perceived as an extremely threatening experience. Privacy embraces solitude, personal space, or intimacy with family and friends and as such, it is a ubiquitous and trans-cultural phenomenon. Privacy leverages well-being; without privacy we are at risk of becoming physically or mentally ill.

Our fundamental need for privacy is contrasted by a second powerful mechanism of social interaction: self-disclosure to others is similarly important for social functioning and psychological well-being. We need to self-disclose to bond with others, form meaningful relationships, and receive social support. A lack of ability to self-disclose causes clinical symptoms such as loneliness and depression.

Striking the right balance between creating private spaces and self-disclosure is a complex task, if not the most challenging one in interacting with others. Today, in times of online communication and the Social Web, this task is further complicated by two confusing facts:

Firstly, our online communication is usually accessible to a vast number of people. On social network sites, it is very common for several hundred online friends to have access to the personal information, status updates, and private pictures of a profile owner. In addition to these online friends as a “known audience,” there are other “unknown audiences,” such as advertisers who purchase the users’ aggregated profile information from social media companies to address their target audiences.

Secondly, many users appear not to feel threatened in terms of their need for and experiences of privacy when communicating online. On social network sites, micro-blogs, or in forums, they publish a vast amount of information that is considered private or even intimate in other contexts. Although they are aware of their data’s publicity on an abstract level, many feel free to speak and to open up to others.