People think there is more violent crime than there used to be, even though violent crime has fallen (see Pew data here). So we should be suspicious when people claim that their neighborhoods used to be so safe that you never had to bother with locks on the doors. Here's a bit of data suggesting that people's neighborhoods are, if anything, safer than they ever were.
The General Social Survey asks folks: "Is there any area right around here––that is, within a mile––where you would be afraid to walk alone at night?". Here's the percentage responding "Yes":