A billion people logged in to Facebook on a single day this week, marking the first time that many members used the world's largest online social network in a 24-hour period. The number amounts to one-seventh of the Earth's population.
Monday's milestone was mostly symbolic for Facebook, which boasts nearly 1.5 billion users who log in at least once a month. But CEO Mark Zuckerberg, who founded the network in his Harvard dorm room 11 years ago, reflected on the occasion with a . . .
