Facebook is a social networking website that allows people to communicate with their friends and exchange information. Launched on February 4 2004, Facebook was founded by Mark Zuckerberg, a former member of the Harvard Class of 2006 and former Ardsley High School student. Initially the membership was restricted to students of Harvard College. It was subsequently expanded to other Boston area schools (Boston College, Boston University, Harvard, Northeastern University, Tufts University), Rochester, Stanford, NYU, Northwestern, and all Ivy League schools within two months. Many individual universities were added in rapid succession over the next year. Eventually, people with a university (e.g .edu, .ac.uk, etc.) email address from institutions across the globe were eligible to join. Networks were then initiated for high schools and some large companies. Since September 11 2006, it has been made available to any email address user who inputs a certain age range. Users can select to join one or more participating networks, such as a high school, place of employment, or geographic region.