Allow me to consider a possible outcome of the notion 'property is theft'. To suggest property rights are a recent political construct is to suggest that your thoughts are anybody's property too. Imagine a society where anything you make can be taken by anyone, and no one has no right to keep anything for themselves. Provided no other person is forcing you, you are free. In order to substantiate that statement lets define terms.
Lets define force.
Such behaviour is characteristic of criminals and governments. This counters efforts at 'proving' a causal relationship between western capitalism and third world poverty. This counters the ludricious notion that a rich man is guilty, by definition, of an impoverished mans' state. Therefore a man who has no material wealth but is not subject to the force of others is as free as a multi-millionaire who also is not subject to the force of others. Freedom has been associated with the volume and quality of opportunities a person has.