Facebook Headquarters

PALO ALTO, CA - MARCH 31: An employee wears his company's colors at the Facebook headquarters, where the atmosphere is casual and laid-back, in Palo Alto, March 31, 2009. Founded in 2004, Facebook is the 10th most visited web site in the world, with some 175 million users who communicate in forty languagues. A private company run by co-founder, CEO and President Mark Zuckerberg, twenty five, Facebook won't divulge its earnings, but it employs 800 people and, like many Silicon Valley companies, provides them with free onsite amenities such as laudry service and restaurants, and a relaxed work environment. (Photo Gilles Mingasson/Getty Images)