Manuel Lora nails the issue of private property:
One must ask how come there are no paparazzi in people's homes? Because they have not been invited. Wherever there is private property, there is order as determined by the owner.
When land and other spaces are socialized such that everyone has generally unlimited access to it at no cost (or very little cost), then we can expect chaos --people will want to have as much use as possible and conflicts over usage rules are almost always inevitable.
It's worthwhile to point out that private property doesn't necessarily mean privately used property. It just means the owner makes the decisions regarding that property, and others must respect those decisions. This is far more scalable than any other scheme.