One thing that slowly changed over my lifetime is that knocking on a stranger's door has become increasingly taboo. Impolite, at least. It isn't that I remember a time of a non-stop parade of strangers knocking on the door, but it was a perfectly normal thing when it happened. Someone walking up the driveway wasn't threatening. Certainly pulling into a someone's drive to make a "u-turn" was standard practice.
Of course it's obscene that anyone is inspired to pull out a gun and start shooting over these things, but how did "someone at my door or in my driveway" start being seen as intrusive behavior at all?
I mean, people shouldn't be pulling out guns and shooting at every perceived threat, but how did these things start being seen as perceived threats?
