[Taken from here.]
I.
Deep in the forest, thousands of miles from civilization, there is an isolated village. It has not seen contact with any other humans for a long time. It is, however, a pleasant and flourishing community, which strongly values freedom and entrepreneurship. There is, however, one tiny quirk. In this village, there is a ritual. Every year, a boy who reaches 18 is cannibalized. It brings the rains, or something. But despite its taste for cannibalism, this village wishes to live in accordance with libertarian principles. Thus, they will only cannibalize the boy if he consents. In order to encourage this to happen, they will put tremendous social pressure on the boy. All through his youth, they will tell him they believe the future of the village depends on his consenting. His parents tell him that he would bring great shame on the household if he refused, which is true. The choice nevertheless rests with the boy, and whatever he chooses will be respected. The parents and villagers attempt to persuade him, but never lie to him, and make clear that they would never force his choice. However: if the boy refuses to be cannibalized, the village has a backup plan. The boy will be blacklisted. No shopkeeper will sell him food, no hotel will give him a room, no hospital will treat him, no employer will hire him. After all, under libertarian principles, nobody can be told how to use their property. The boy’s parents, ashamed of him, will turn him out of the house with no money. He may leave the village, but it is certain death, for thousands of miles of desolate wolf-infested wilderness stand between him and other humans and he has no food. (The wilderness is also privately-owned, and he cannot pay the admission fee.) He is shunned and despised, left to wander the streets in a futile search for shelter and sustenance. However, no force is exercised against him. He is never touched or arrested. He is treated as nonexistent, as the villagers await his demise. So the boy starves to death. The villagers then cannibalize his emaciated corpse, reasoning that they cannot be compelled to give him a dignified burial (plus he died on private property, collapsing in a flowerbed).