All the people I know are taking common sense precautions (including my wife and me). Do you know a lot of people who aren't?

I do. A shit ton. Most people I've talked to, in fact. Not that it matters who you or I know. Option 4 is the same as option 3: do nothing like the UK. People will act in what they perceive is their own self interest. For most people, that does not align with what's good for society. It's too late for mass testing. There's only one option: lock down.

I'm taking common sense precautions.

There are parents at my kids' schools rolling their eyes and planning playdates. The local ski hill closed and people are complaining falsely "it's less lethal than the flu". There are people filling bars all over the country.

It doesn't take all that many of these people to flood the hospital ICUs - which already run pretty full in normal times - well beyond capacity.