Decades old and still completely relevant, "Culture of Fear":
https://www.amazon.com/Culture-Fear-Americans-Afraid-Things/...Also, in my experience older people just get more paranoid. I have seen it happen with family members who are otherwise pretty sharp. They get more wary or suspicious in ways that aren't very rational. Since that is a lot of the folk who hang out on places like Nextdoor, I can see how that goes. That's why you need diversity and young families in neighborhoods. It provides balance.