- Site adds a header if they may potentially have adult content.

- Browser detects header. Prompts for local password to access site.

- Child does not know password, picks a different site or begs parent for access.

- This is now between small child and parent. No third parties, no tracking, no telling website the users age, no local or remote API's sharing data.

- At some point if all goes well the child will be an adult and will thank their parent for looking out for them when all their friends data was sold and abused.