Facebook has 1.32bn monthly active users, inc 1.07bn mobile monthly active users

"Daily active users (DAUs) were 829 million on average for June 2014, an increase of 19% year-over-year.
Mobile DAUs were 654 million on average for June 2014, an increase of 39% year-over-year.
Monthly active users (MAUs) were 1.32 billion as of June 30, 2014, an increase of 14% year-over-year.
Mobile MAUs were 1.07 billion as of June 30, 2014, an increase of 31% year-over-year."

Source:  Facebook Q2 2014 Results, 23rd July 2014
Earlier - 1.15bn and 819m in Q2 2013