This is from a while back but worth a mention nonetheless.
In the New York Sun, Lenore Skenazy describes how one weekend she gave her son a travel pass and allowed him to explore New York on his own using the subway and bus network.
In the updated article, she describes the response to her original story;
Half the people I’ve told this episode to now want to turn me in for child abuse. As if keeping kids under lock and key and helmet and cell phone and nanny and surveillance is the right way to rear kids. It’s not. It’s debilitating — for us and for them.
I for one admire Mrs Skenazy’s approach. I know my own kids don’t have anywhere near the liberty I had when I was growing up and I worry sometimes about what they might be missing out on.