These days a single killer or predator anywhere on the same continent can strike fear into the minds of millions of people, and do so at the speed of light (in fiber optic).
Naturally you'd expect this to result in a much higher base level of fear, as compared to when your community was just people you knew and trusted personally.
This is it. TV and the internet have made society more fearful. I think America's Most Wanted was a turning point as far as child rearing was concerned. This show sowed and sold parental fear.
I agree that this is probably the predominant factor. Even with my own life, many of my friends and coworkers think I am risking my life somehow when I ride the bus and train in to work. I'm like, have you actually ridden the thing? Sure there are a couple drug addicts and transients but the majority of the riders are just people trying to get across town and I've never once felt unsafe. But try and explain this and its like they refuse to value your actual lived experience in favor of the fear they have bit into hook line and sinker.
Naturally you'd expect this to result in a much higher base level of fear, as compared to when your community was just people you knew and trusted personally.