With more than 1 billion users, Facebook is one of the most popular social networking sites. After users create a personal profile or organization page and add photos, contact information, and additional information, they can search for people with similar interests, create networks of “friends,” communicate by sending private messages or posting comments on another user’s wall, “like” pages of organizations and join “groups” with other users who share similar interests, and post and share content created on Facebook or linked to another website.