Article Photos: Facebook gets unwelcome look at hackers' dark side 1/1

This Feb. 8, 2012 photo shows a mural at Facebook headquarters in Menlo Park, Calif. Intruders recently infiltrated the systems running the world's largest online social network but did not steal any sensitive information about Facebook's more than 1 billion users, according to a blog posting Friday, Feb. 15, 2013, by the company's security team. (AP Photo/Paul Sakuma)