The founders had initially limited the website's membership to Harvard students; however, later they expanded it to higher education institutions in the Boston area, the Ivy League schools, and Stanford University.Facebook gradually added support for students at various other universities, and eventually to high school students as well.Facebook makes most of its revenue from advertisements which appear onscreen. held its initial public offering (IPO) in February 2012, and began selling stock to the public three months later, reaching an original peak market capitalization of 4 billion.On July 13, 2015, Facebook became the fastest company in the Standard & Poor's 500 Index to reach a market cap of 0 billion.After registering to use the site, users can create a user profile indicating their name, occupation, schools attended and so on.Users can add other users as "friends", exchange messages, post status updates and digital photos, share digital videos and links, use various software applications ("apps"), and receive notifications when others update their profiles or make posts.Additionally, users may join common-interest user groups organized by workplace, school, hobbies or other topics, and categorize their friends into lists such as "People From Work" or "Close Friends". Additionally, users can complain about or block unpleasant people.Because of the large volume of data that users submit to the service, Facebook has come under scrutiny for its privacy policies.
Facebook may be accessed by a large range of desktops, laptops, tablet computers, and smartphones over the Internet and mobile networks.
To accomplish this, Zuckerberg hacked into protected areas of Harvard's computer network and copied private dormitory ID images.