If he really thought that libertarianism was a good system, would he be okay with me expressing my freedom to use the resources he considers his? Or would he want government enforcement to maintain "his" resources?
If that freedom of expression is speech and associated freedoms, then yes, why not?
Perhaps there are anarchist libertarians who say there is no need for property rights enforced by government. However, I suspect those same people would also support a right to bear arms (without a government who except themselves could enforce such a right?) and, without a government to enforce the even deeper property right of assault laws, I can see calamity there, probably for you.
Pretty much all libertarians favor some mechanism for the enforcement of property rights. They may differ as to how, but they agree that you shouldn’t be allowed to steal other people’s stuff.
(Please, I beg you, argue with the opinions that people actually have instead of something you just made up.)
Perhaps there are anarchist libertarians who say there is no need for property rights enforced by government. However, I suspect those same people would also support a right to bear arms (without a government who except themselves could enforce such a right?) and, without a government to enforce the even deeper property right of assault laws, I can see calamity there, probably for you.