Facebook Readies IPO FilingFacebook in Photos

Facebook CEO Mark Zuckerberg delivered a keynote talk during the Facebook f8 Developer Conference at the San Francisco Design Center on Sept. 22, 2011.

Mark Zuckerberg and his Facebook co-founder Dustin Moskovitz at Harvard Yard in Cambridge, Mass. Facebook was co-founded in 2004 by the then-Harvard University students.

Mark Zuckerberg spoke to media and advertising partners at an event in New York in November 2007.

Mark Zuckerberg delivered a keynote address at the annual f8 conference in San Francisco in April 2010.

Mark Zuckerberg spoke with reporters after announcing the launch of Facebook Places—an application that allows Facebook users to document the places they have visited—in Palo Alto, Calif., in August 2010.

Mark Zuckerberg greeted employees before speaking at a news conference in Palo Alto in October 2010. He announced the addition of a revamped personal groups feature and the ability to download items that users post to Facebook.

Cameron, left, and Tyler Winklevoss, founders of social networking website ConnectU, left an appeals court in San Francisco in January 2011. They had accused Mark Zuckerberg of using their ideas to found Facebook.

President Barack Obama spoke with Mark Zuckerberg during a town hall style meeting at Facebook headquarters in Palo Alto in April 2011.

From left, German Chancellor Angela Merkel, French President Nicolas Sarkozy, Publicis Group CEO Maurice Lévy, Mark Zuckerberg and Google Chairman Eric Schmidt spoke at the G8 summit in Deauville, France, in May 2011.

Mark Zuckerberg and comedian Andy Samberg shared a laugh during Mr. Zuckerberg's keynote address at the f8 conference in San Francisco in September 2011.

In this undated publicity image, Jesse Eisenberg, left, and Joseph Mazzello acted in the 2010 movie 'The Social Network,' which dramatizes the founding of Facebook. Mr. Eisenberg played Mark Zuckerberg.