My wife was raised in a suburb just outside of Chicago. She was raised with a high level of paranoia. Trust no one, trust nothing. Personal safety is one thing, property, I rather be smart, not waste energy worrying. We see things very differently at home and in the campgrounds.
That being said, in the 5 years we've been married, she is learning to relax. She is learning that the good people out there, outnumber the bad. It is okay to leave the basics set up outside. There are much better uses of energy, than living in fear that someone is waiting around the corner to rip you off.