FB said in SEC filings that many young people lie about their age when signing up; independent research I've found confirms that FB uses self-reported age for a

FB said in SEC filings that many young people lie about their age when signing up; independent research I've found confirms that FB uses self-reported age for ad targeting (https://www.demogr.mpg.de/papers/working/wp-2021-006.pdf https://www.demogr.mpg.de/papers/working/wp-2021-006.pdf). British authorities say more than 80% of children lie about their age (https://www.theguardian.com/media/2013/jul/26/children-lie-age-facebook-asa https://www.theguardian.com/media/2013/jul/26/children-lie-a...). More search shows that parents often encourage their kids to lie about their age when signing up (https://journals.uic.edu/ojs/index.php/fm/article/view/3850/3075 https://journals.uic.edu/ojs/index.php/fm/article/view/3850/...), presumably under the belief that it'll make them less likely to be targeted by predators. FB has used algorithms since 2011 to try to ban underage users (https://www.nytimes.com/2011/03/12/technology/internet/12underage.html https://www.nytimes.com/2011/03/12/technology/internet/12und...) but presumably there's an error rate, and it's bad PR for normal adult users to be asked to submit their ID/passport to keep access to their account, so it's a hard problem. It's easy to paint FB employees as cravenly evil cartoon characters, but most FB ads (except ones from the biggest corporations) are "direct response", i.e. not focused on increasing brand awareness but on immediately funneling users to a sales page. FB doesn't benefit from underage kids, who have zero spending ability, from seeing direct response ads (obviously, brand awareness ads on underage people are hugely effective, however), it just messes up their ad targeting. It seems to be a hard problem to solve when you consider all factors.