The Facebook logo is displayed on a computer screen in Brussels April 21, 2010. Over the past six years, social networking has been the Internet's stand-out phenomenon, linking up more than one billion people eager to exchange videos, pictures or last-minute birthday wishes. Picture taken April 21, 2010. To match feature: INTERNET-SOCIALMEDIA/PRIVACY REUTERS/Thierry Roge (BELGIUM - Tags: BUSINESS SOCIETY)