I understand the policeman’s motivations, but the idea that the answer to abusive scammers is that we should reduce our level of trust in society generally is severely damaging.
I don't answer the phone or the door unless I know someone is coming or I'm expecting a parcel. And I have a huge 6 D cell flashlight by my bed (that I will not hesitate to use as a weapon)
Granted I don't live in a suburb but in an inner city in Europe.
When you're in a suburb, a stranger directly outside your house for any amount of time is far less likely to be a friendly just going about their day,
like it would be in a small town or in a city.
Learned reactions. Ugly overreactions, often. But, learned.