Tbd how many U.S. middle school systems effectively require a Facebook account at this point, e.g., to coordinate student group projects; tangentially, see Consensus view now appears to be to guide children’s screen-time, not limit it (9to5Mac)
"Cook's nephew will soon be a teenager. The minimum official age to have a Facebook account is 13, yet some have said for years that this is regularly flouted. Some estimates have put Facebook participation among under-13s at 7.5 million.Tim Cook: I keep my tween nephew away from social networks - CNET
A recent UK study showed that 51 percent of 12-year-olds and 28 percent of 10-year-olds have a social media profile.
In December, perhaps to address this reality, Facebook launched a Messenger Kids app specifically for the under-13s."