Facebook is an American online social media and social networking service based in Menlo Park, California, and a flagship service of the namesake company Facebook, Inc. It was founded by Mark Zuckerberg, along with fellow Harvard College students and roommates Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes. ,The founders initially limited Facebook membership to Harvard students. Membership was expanded to Columbia, Stanford, and Yale before being expanded to the rest of the Ivy League, MIT, and higher education institutions in the Boston area, then various other universities, and lastly high school students. Since 2006, anyone who claims to be at least 13 years old has been allowed to become a registered user of Facebook, though this may vary depending on local laws. The name comes from the face book directories often given to American university students. ,Facebook can be accessed from devices with Internet connectivity, such as personal computers, tablets and smartphones. After registering, users can create a profile revealing information about themselves. They can post text, photos and multimedia which is shared with any other users that have agreed to be their "friend", or, with a different privacy setting, with any reader. Users can also use various embedded apps, join common-interest groups, buy and sell items or services on Marketplace, and receive notifications of their Facebook friends' activities and activities of Facebook pages they follow. Facebook claimed that it had more than 2.3 billion monthly active users as of December 2018, and it was the most downloaded mobile app of the 2010s globally. ,Facebook has been the subject of numerous controversies, often involving user privacy, political manipulation, mass surveillance, psychological effects such as addiction and low self-esteem, and content such as fake news, conspiracy theories, copyright infringement, and hate speech. Commentators have accused Facebook of willingly facilitating the spread of such content. , ,Zuckerberg built a website called "Facemash" in 2003 while attending Harvard University. The site was comparable to Hot or Not and used "photos compiled from the online face books of nine Houses, placing two next to each other at a time and asking users to choose the "hotter" person". Facemash attracted 450 visitors and 22,000 photo-views in its first four hours. The site was sent to several campus group listservs, but was shut down a few days later by Harvard administration. Zuckerberg faced expulsion and was charged with breaching security, violating copyrights and violating individual privacy. Ultimately, the charges were dropped. Zuckerberg expanded on this project that semester by creating a social study tool ahead of an art history final exam. He uploaded all art images to a website, each of which was accompanied by a comments section, then shared the site with his classmates. ,A "face book" is a student directory featuring photos and personal information. In 2003, Harvard had only a paper version along with private online directories. Zuckerberg told The Harvard Crimson, "Everyone's been talking a lot about a universal face book within Harvard. ... I think it's kind of silly that it would take the University a couple of years to get around to it. I can do it better than they can, and I can do it in a week." In January 2004, Zuckerberg coded a new website, known as "TheFacebook", inspired by a Crimson editorial about Facemash, stating, "It is clear that the technology needed to create a centralized Website is readily available ... the benefits are many." Zuckerberg met with Harvard student Eduardo Saverin, and each of them agreed to invest $1,000 in the site. On February 4, 2004, Zuckerberg launched "TheFacebook", originally located at thefacebook.com.