No matter how old, frail or vulnerable it may be, a life isn’t something to take or risk at another’s discretion. Nor does it undermine culpability when someone dies as a result of negligence. The common law ‘eggshell skull’ rule reflects this moral principle.
During the Coronavirus pandemic, some erstwhile defenders of the famous Non-Aggression Principle (NAP) appear to have forgotten that natural rights are conceived to protect life as well as liberty and property. They seem to think that the liberties we ordinarily enjoy have priority over the right to life of others. The environment has changed and, for the time being, many activities that we previously knew to be safe for others are not. They are not part of our set of liberties until a reformed set of rules, norms and habits establishes a sufficiently hygienic public environment. To say that bans on public gatherings violate natural rights a priori is as untenable as G.A. Cohen’s claim that a prohibition on walking onto a train without a valid ticket is a violation of one’s freedom.
The clue for anarcho-capitalist state-sceptics that this is a genuine shift in social priorities is that even organized criminal gangs are willing to enforce social distancing. You do not have to believe that the state itself is legitimate to see that the need for social distancing is sufficiently morally compelling that it can be enforced absent free agreement, just as one does not need free agreement to exercise a right to self-defense.
Not every restriction is going to be justified, although erring on the restrictive side makes sense while uncertainty about the spread of infection persists. Ultimately, restrictions have to balance genuine costs with plausible benefits. But rejecting restrictions on a priori grounds does not cohere with libertarian principles. Right now, our absolute liberties extend to the right to be alone. Everything else must be negotiated under uncertainty. Someone else’s life, even two-weeks or so in the future, is a valid side-constraint on liberty. People can rightfully be made to stay at home if they are fortunate enough to have one. When people have to travel out of necessity, they can be temporarily exempted, compensated or offered an alternative reasonable means of satisfying their immediate needs.