I don't know about fear, though it's certainly a concern. I have had police and social workers come to my home, and to my child's school, because I let her walk to the park alone. The park was less than 100 meters from my home.

In my own childhood--an objectively more dangerous time--I explored an area of over 100 square kilometers, unsupervised and with no means of phoning home, yet suffered no problems more serious than a skinned knee.