Anarcho-capitalists, like other libertarians and classical liberals, only believe property is legitimate when it has been gotten in the right sort of way.  If you steal (take something from someone without their permission), or hire someone to steal on your behalf, or ask the government to steal on your behalf, the property you get is not really yours.  The "real" owner is still the person or people it belonged to before it was stolen.  Anarcho-capitalists say that governments do not legitimately own anything, since governments get all of their wealth through force, including taxation and counterfeiting. Because anarcho-capitalists support private property, they believe that a person can own a building or land without actually using it. They believe that these things can be protected by private security guards.