It seems like it would be hard for a parent or the community to monitor kids' social media use in a way that's appropriately hands-off. Maybe mandate that users under 18 have parental consent and give the parent access to something limited, like a graph of contacts with their frequency of interaction.

That would be akin to a parent's ability to see who their kid is hanging out with in real life, without the extent of listening to every word they say.

In the US, the “community” calls the police if a parent let’s the child walk to school. I’m pretty sure that qualifies for “overreaching”.

In the US the community didn't use to do that at all.

It has been taught to do so, assisted by the government (overzealous social services, etc), academic "experts" of all kinds, and hysterical media.

This is a very nice piece of writing from the Austin Chronicle that tells the story of a much freer US and community:

http://michaelventura.org/wp-content/uploads/2013/04/This-Is...

Parents are part of the community?

Yes, but a part is not the whole -- and even less so a very small part.

So the parents doing it is not the same as the community doing it.