So we should have no borders. Okay, lets see where that leads us.
We should have no borders around any real property. By consistent logic, your home is not your own and you have no justification in preventing someone else deciding that they'd like to move in.
But if real property is not ring fenced, what about personal property? Well, isn't it unjust to prevent someone from taking anything you have?
But if personal property is not sacrosanct, why is the human person not common property? So I should be permitted take what I want from another human being without their consent, down to violating their body.
These people are idiots. By their arguments all crime of whatever nature is permissible because boundaries should not exist. But, of course, they will be the first to cry when rampant violation of rights hits them where it hurts.