High Quality Content by WIKIPEDIA articles! Social networking sites greatly vary in the levels of privacy offered or even required. With some sites, such as Facebook, the use of real names and uploading of personal information is encouraged (onto a page known as a ‘Profile‘). This may include birthday, address, telephone number, and more intimate details such as interests, hobbies, favorite books/films/music, relationship status. There are others, such as Match.com, where the use is designed to encourage anonymity, and thus linking users to individuals can be difficult. However, even with sites that discourage the use of real names, individuals can be identified, such as through face re-identification. It has been estimated by studying two major social networking sites that a 15% overlap of the same or similar photographs makes it possible to identify profiles with similar pictures on other sites. With sites that do encourage information disclosure, it has been noticed that the...