Facebook is a social network founded in February 2004 by Mark
Zuckerberg and his fellow students. Originally created for the students
of Harvard University, it was made available to students from any
university in the U.S. In September 2006, it was open to anyone in the
world, to connect with relatives, friends, and strangers. It was become
the second most visited website in the world, after Google, with 500
million users in June 2010, while sparking debates on privacy issues.