There are not property rights and there is no security except the security that human beings create for themselves and, ultimately, one another. "Property rights" do not descend from the platonic realm to protect you if someone invades your home. You may protect yourself or your neighbors may protect you or, as is more generally the case, I believe, a general sense of bonhomie shared by human beings everywhere, does most of the protecting. But the rights are a mere convention cooked up by people, for people, and even then they are more a symbolic act against the barbarism of the sorts of sociopaths who show up with soldiers and decide they are the kings.

It's true that now those kinds of people are often directed towards politics and become the elected officials which you assert justify the borders, but in fact most of the borders we live with were never drawn with any consent of the people living there. The vast majority of borders are pure objects of fiat power (especially the border over which the immigration you have a chip on your shoulder about, which was quite literally determined via war).

Herein I'm not advocating charity, which is, nevertheless, a fundamental human virtue. I am advocating that human beings, if they have any rights or dignity at all, have those rights and dignities by virtue of their humanity and not by virtue of where their parents happened to be when they were born. Communities of humans shouldn't tolerate freeloaders, but the people coming across the border are by and large the exact opposite: people willing to work harder for less than many people living here. If you are really so concerned with social parasites, let me suggest you look to institutions like health insurance companies, landlords, etc.