In the house where I grew up， it was our custom to leave the front door on the latch at night。 I don't know if that was a local term or if it is universal; "on the latch" meant the door was closed but not locked。 None of us carried keys; the last one in for the evening would close up， and that was it。
Those days are over。 In rural areas as well as in cities， doors do not stay unlocked， even for part of an evening
It has been replaced by dead-bolt locks， security chains， electronic alarm systems and trip wires hooked up to a police station or private guard firm。 Many suburban families have sliding glass doors on their patios， with steel bars elegantly built in so no one can pry the doors open。
The lock is the new symbol of America。 Indeed， a recent public-service advertisement by a large insurance company featured not charts showing how much at risk we are， but a picture of a child's bicycle with the now-usual padlock attached to it。
