Mass quarantines as a last resort are still perfectly consistent with a philosophy that prizes personal freedom

The kind of people who say ‘if you like freedom so much, why don’t you move to Somalia?’ think that libertarians have been “owned” by the coronavirus. If you oppose the nanny state but want to contain the epidemic, you are apparently some kind of hypocrite. How can libertarians ever support mandatory quarantine and nationwide lockdowns?

Quite easily, as it happens. I can’t speak for all libertarians (who can?) but I see libertarianism as applied economics. The government should leave businesses alone unless there are demonstrable market failures and it should leave people alone unless they are doing direct harm to others.

In case it is not obvious, infecting somebody with a potentially fatal virus counts as direct harm to others.

Let us assume that Coronavirus is far more dangerous than seasonal flu and has the potential to kill millions. If so, it is a classic public health problem. It carries serious negative externalities and can only be dealt with by collective action. There are things you can do as an individual to reduce your risk - wash your hands, cancel non-urgent appointments, etc. - but you will still be at risk.