Didn't we (sort of) try age restriction metadata during the '90's with P3P? (or a closely related technology.. the name escapes me)
If you tightened the settings in Internet Explorer it would only allow you to access sites with P3P data - which was pretty much _nothing_ on the internet.
If you tightened the settings in Internet Explorer it would only allow you to access sites with P3P data - which was pretty much _nothing_ on the internet.
https://en.wikipedia.org/wiki/P3P