When did we become a nation of police informers?

There’s a danger that in what follows your columnist may seem to be recommending an attitude. Please don’t think that. It’s true that I would never shop a friend for drink-driving — but frankly I doubt I’d shop a friend for murder. This column isn’t about what we should do if we know a friend drink-drives — responses will be various and variously arguable — but about shock at my own serious misreading of my countrymen.