What technical implementation will be used to verify the user age? - Taking pictures of children seems something that will go horribly bad - Government verific

What technical implementation will be used to verify the user age? - Taking pictures of children seems something that will go horribly bad - Government verification is not implemented, even in countries were it is possible to verify your identity on-line (to pay taxes or so) it still lacks safe and anonymous way to verify age. - Sending IDs like passports and so will be a source of hacking and identity theft. I am all for having a government sanction service that allows me to send them a session key and they sign it as I am an adult. The government does not need to know from where the key comes from and the service does not need to know my ID. Just age verification.