I specified private property (absentee ownership), which is distinct from personal property (active usage ownership).
A house that I live in: personal property. A house I rent to someone else so they can live in it: private property.
That doesn’t change anything, does it? What’s stopping people from kicking me out of whatever place I am living in because they want it instead?
The self-defensive mechanisms established by the community I live in.
Anarchism doesn’t mean that humans can’t form societal structures. It just means that decisions are made bottom-up instead of top-down.
Hierarchical society doesn’t stop anyone with “higher rank” from claiming my house e.g. to build a highway or coal mine.
How would an anarchist society stop someone from claiming your house to build a highway or a coal mine? “The self-defensive mechanisms” is just police again you just call it differently and it can do whatever it likes.