Facebook CEO Mark Zuckerberg, second from right, speaks with Director of Engineering Lars Rasmussen at Facebook headquarters in Menlo Park, Calif., Tuesday, Jan. 15, 2013. Zuckerberg in

 

              Facebook CEO Mark Zuckerberg, second from right, speaks with Director of Engineering Lars Rasmussen at Facebook headquarters in Menlo Park, Calif., Tuesday, Jan. 15, 2013. Zuckerberg in
Facebook CEO Mark Zuckerberg, second from right, speaks with Director of Engineering Lars Rasmussen at Facebook headquarters in Menlo Park, Calif., Tuesday, Jan. 15, 2013. Zuckerberg introduced “graph search" Tuesday, a new service that lets users search their social connections for information about their friends’ interests, and for photos and places. (AP Photo/Jeff Chiu)