I don't think things are that different today - I think it is the perception that the world is a more dangerous place. Faces on milk cartons, Amber Alerts, 24 hour news channels,we hear about it more and sooner.
We had a child molester living across the street from us, I remember my mum sitting us down and explaining it to us. This was 50 years ago. Another kid who used to baby sit in the neighborhood was also a child molester.
We hear nowadays about how many millions of kids are "missing" every year - 99% of them are non-custodial parent abductions - not stranger abductions.
PS - how do you play Ghosts in the Graveyard - that sounds fun!
Plus there were no cell phones, so there was no way for parents to keep in touch with their kids 24/7 unless they kept them in sight.
I think kids today suffer greatly from being overly supervised and scheduled. Spontaneous, undirected play, is an important part of a kid's development. I cringe when I see 5 and 6 year olds on an organized sports team, what is wrong with just turning them loose in a field with a ball and letting them make something up?