Many people on ASC seem to be limiting the scope of their broader philosophical thinking to libertarianism, and in terms of further exploration or debate limit themselves to the dwindling dicussions occuring on the ASC forums. In this milieu debates over fine points of the non-agression principle, like who owns the airspace above your house, assume cosmic importance.

Though some may mistake its originator Murray Rothbard for a messianic figure, the NAP doesn't answer all ethical questions. It is unnecessary to take it to extreme lengths, and defend it with such zeal. There are of course situations where it will not work well, and these especially come in to play when defining what is your property, and what exactly is "aggression".

Really, the NAP is just a more specific application of Kant's Categorical Imperative: "Act only according to that maxim by which you can at the same time will that it would become a universal law." Of course, a libertarian would act in accordance to the NAP, while a communist would not. That is what distinguishes a libertarian, and why the concept of the NAP is a good way to understand libertarian thinking. But by being more specific, the NAP can become more inflexible. Sometimes we have to decide things based on a specific situation and not just refer back to a general principle. Can you really know how hypothetical cases judged by hypothetical judges in a hypothetical market anarchist society will play out? Go ahead and try, but if your head explodes, don't blame Rothbard.