Founded by Mark Zuckerberg in 2004, Facebook was a Harvard-exclusive network that quickly spread to other schools, companies, and finally to everyone in 2006. In 2008, Facebook became the most popular social network site in the world and continues to grow. According to statista.com, Facebook has over 1.4 billion users as of 2015 and is the first social site to reach the billion mark. While Facebook doesn't allow its users as much customization as Myspace, it does allow users to post images and videos that personalize their content. Facebook also has private messages and wall posts. Wall posts are viewed by other friends, generally unseen by the public. Facebook also allows users to set privacy to control who can access theirs