Total control and dictatorship
What you request is TOTAL CONTROL over content a uset can use. The thing you request, is a tool used bx DICTATORS to CONTROL peoples and not to protect em. It seems, you are not aware, HOW DANGEROUS your request is, because once such control is in place, you can restrict ANYONE! If you need something like a Digital ID to surf the internet, everyone involved can track you down to the second. I am an ex high ranking french military (also Cyberdefense 1999-2007) living in Estonia since 2016 with an Enterprise, I have a very broad experience in SURVEILLANCE. WHAT YOU REQUEST can be misused at any time WITHOUT YOUR KNOWLEDGE. The only usefull thing I can imagine is 1) create a database of indexed website and put a recommended age rating on it 2) private internet devices should have a client software installed which access the database in 1) 3) the internet access device should allow "parental control" where the parrents can override the "recommendations" by the database 1) This allow to do the restrictions verry effective without involving authorities to track every movement you make. This is EASY to implement and this FIREWALL can be active by default on every Internet Router (DSL, GSM, LTE) and also on SmartPhones. To unlock the Internet Accesd Devices you nrrd only ONCE to identify yourself with your ID to vetify, the ADMINISTRATOR of the IAD is older then 18 years. This can be done with the SmartID, MobileID or ID-Card. Happy new year