Social media giants could be ordered to use facial recognition to check children’s ages under plans to be set out next spring. Millions of kids would have their profiles taken down from online sites with tech giants warned they will be punished if they break the new rules. Ofcom, the online regulator, will announce guidance social media firms must follow to make sure their users are not under age. As many as 60% of eight to 11-year-olds have social media profiles, according to Ofcom’s estimates.