> You wouldn't allow your child to walk up to random strangers in the street without you there
This applies to under 16 year olds though, not little children but adolescents. I would hope that every parent of teenagers allows them to talk to random people on the street.
Instead of binary it should be tiered, complete monitoring of online activity of child till say age 8, to gradually opening the circle till age 14-16. We do it for movies/games.