This works, ultimately, because the frail old lady can call the police, who outnumber and outgun the strong young men. There is admittedly also an element of m

This works, ultimately, because the frail old lady can call the police, who outnumber and outgun the strong young men. There is admittedly also an element of magic here: People generally view property rights as legitimate, and the police who enforce them as legitimate, and so on. But when that belief system fails, it's ultimately the State's ability to deploy force that reestablishes the faith.