**FILE** President Obama and Facebook CEO Mark Zuckerberg take off their jackets at Facebook headquarters in Palo Alto, Calif., on April 20, 2011, before their joint town-hall meeting to discuss reducing the federal deficit. (Associated Press)
This screenshot made on Friday, Feb. 4, 2011 shows Dr. Edward Zuckerberg's Facebook page. Dr. Edward Zuckerberg, father of Facebook CEO Mark Zuckerberg, said in a radio interview Friday that Mark's early exposure to computers helped inspire his interest and expertise in technology. Dr. Zuckerberg also said he uses Facebook to promote his dental practice and spends about an hour a day on the site. He also still does Mark's "routine dental care." (AP Photo/Facebook) NO SALES; EDITORIAL USE ONLY
FILE - In this Nov. 16, 2010 file photo, Facebook CEO Mark Zuckerberg smiles as he speaks at the Web 2.0 Summit in San Francisco. Zuckerberg has been named Time magazine's "Person of the Year" for 2010. (AP Photo/Paul Sakuma, File)
Mark Zuckerberg, co-founder and CEO of Facebook," called the Time selection "a real honor." He's the youngest choice for the honor since the first one chosen, Charles Lindbergh in 1927.
FILE - In this Nov. 15, 2010 file photo shows Facebook CEO Mark Zuckerberg smiling at an announcement in San Francisco. Another 17 of America's richest people, including Zuckerberg, junk bond pioneer Michael Milken and AOL co-founder Steve Case, have pledged to give away most of their wealth. They are the latest to join the Giving Pledge, an effort led by Microsoft founder Bill Gates and investor Warren Buffett to commit the country's wealthiest people to step up their charitable donations. (AP Photo/Paul Sakuma, file)
FILE In this Wednesday, Oct. 17, 2007 photograph, Facebook founder Mark Zuckerberg smiles during a talk at Web 2.0 conference in San Francisco. Several media outlets reported Wednesday, Sept. 22, 2010, that Zuckerberg is going to donate $100 million to Newak's public school system, which has has some of state's lowest test scores and poorest graduation rates. On Oprah Winfrey's Chicago-based syndicated television show Friday, Sept. 24, 2010, Democratic Newark Mayor Cory Booker, Republican Gov. Chris Christie and Facebook founder Zuckerberg are expected to announce the donation. (AP Photo/Paul Sakuma,file)
Facebook CEO Mark Zuckerberg, right, talks with employees before announcing the social network site's new localization services called "Places" during a press conference in Palo Alto, Calif., on Wednesday, Aug. 18, 2010. (AP Photo/Tony Avelar)