We have a right not to be aggressed against. Any other right has to be an application of my right not to have force initiated against me. Now, we need to do this with property rights. We need to treat the violation of property as aggression against self.
Locke says that, because privately owned land is more productive than publically owned land, you have increased the common stock of mankind when you appropriate it. Should there be exceptions to rights for emergencies? Yes. Contracts have to be sustained to be enforceable. You can contract yourself into indenture, but not into lifelong slavery.
The seventh of ten lectures from the Foundations of Libertarian Ethics seminar with Roderick T. Long.