Underage Facebooking: Half of All 12-year-olds Use Social Networks, Study Says
Facebook officially forbids children under the age of 13 from using the site but, according to a study from the Pew Internet and American Life Project, there are plenty that do. About 46-percent of all American 12-year-olds use social networking sites, compared with 62-percent of 13-year-olds. It's worth pointing out that Pew's data is from September 2009, so there's a very real chance that these numbers have risen since then.
Facebook's Public Policy and Online Safety team does its best to identify minors who may be lying about their age, but it's an understandably difficult task. Complicating the team's job is the fact that many parents don't have a problem with their kids using Facebook, even if the site says they're too young to do so.
It should also be noted that Pew's study didn't examine social network use among kids younger than 12. If it turns out that half of all 5-year-olds are on Facebook, we might have a crisis on our hands. But it's hard to justify sounding the alarms when a bunch of middle-schoolers are doing something a few months before they're "supposed" to.