Yeah though chloroquine is fairly mild stuff - they used to give it to all travellers going to malarial places but have mostly stopped because malaria mostly became resistant. I'm not a medic but reading the letter to nature I'd put the odds of it protecting you in real life at say 50/50 so if you're getting exposed it could be a reasonable risk reward. Even if it didn't stop infection it could make the illness less severe.

I avoid touching my face, stay away from crowds (not that I didn't before, hah!), cough / sneeze into tissue / handkerchiefs, wash my hands properly and have a bottle of sanitizer at all times.

I might need more measures if I was in the middle of Wuhan (or even just feeling ill, I guess) but frankly where I am it feels like any additional steps would be done out of fear, not reason.

When a building is burning, often, people's first reaction is to ignore the alarm and carry on with what they were doing. The first people to leave look like worry-warts. Those who make it out, though, are the ones who think for themselves and realize there is a problem, before the herd stampedes. Insurance is cheap before there's a problem, but impossible to get after. What is my "cost" and "risk" from having chloroquine? I'll probably never take it, so almost nothing. What is my upside? Maybe nothing, maybe everything.

I hear a lot of "it is just the flu." Maybe. The Spanish Flu was horrific, though. And when was the last time a city the size of london was quarantined for the flu?

I believe in data-driven fear. Care to go over the data?