Philosophy warning: I don't know if there is a term for it, or if a philosopher/etc. has written about this phenomenon, but: a noticeable trend to me is what I'll call "the replacement of ethical expectations with specific, written down laws." Rather than expecting a human being to behave in certain ways intrinsically (i.e., normative ethics ) we tend to assume they will behave in the worst way possible, and then pas…
It's simply the way of the world. I don't believe it's change materially, except to the degree that the ability to self defend (e.g. better locks) and to identify miscreants (e.g. cameras) has improved.
I do feel that there are more private security guards than there used to be but when I watch old movies I'm not sure my impression is correct.