Facebook is currently the largest social network in the world. It was created in February 2004 by Mark Zuckerberg and his Harvard University colleagues as a private network for alumni of Harvard and subsequently other American universities and educational institutions. In September 2006, it became a public worldwide network for anyone over 13. Since the early 2010s, it is the most popular social media website in most countries, with notable exceptions such as Russia where VK is more popular.
The website is the subject of government censorship and criticism. Access to it is blocked in the People's Republic of China since 2009 and has previously been blocked in Iran and Bangladesh as well. Facebook has been said to cause addiction and to uphold certain political views while opposing and censoring others.