Well, in those days IRL, everyone's name, address and phone number were publicly available in the phone book, you would answer all phone calls without knowing w

Well, in those days IRL, everyone's name, address and phone number were publicly available in the phone book, you would answer all phone calls without knowing who was calling, and it wasn't a problem is it was someone you didn't know; same for visits. Nowadays, each of those is seen and felt as a terrible violation of your privacy, your intimacy, your property even... and people often rather play possum than take the 'risk' of picking up the phone or opening the door when the phone or the door bell rings. When you call someone who hasn't got your number already, you are initially met with hostility (in the lucky case the person even picks up the phone) and have to justify "how the hell did you get my number?"