1. A shepherd comes across a lush isolated pasture. A villain finds out and threatens to reveal the location of the pasture to other shepherds unless he pays up. The shepherd refuses, and a tragedy of the commons ensues. (Replace the pasture with, e.g., a fishing spot to make it more difficult for the property rights to be defined or enforced.)
   
   
2. The government, having learned of the completion of the human genome project by Celera, secretly installs spying software on the firm's computers and later threatens to nationalize its discovery unless certain interested parties are given $2 million each.
   
   
3. Rome is besieged by a barbarian horde. A traitor tells the magistrate that unless the city pays him one hundred talents of gold, he will reveal to the barbarian chieftain a secret passage to the city that only he knows.
   
   
4. Scientists have genetically engineered a deadly virus. A spy steals the data and threatens to sell it to the terrorists who intend to release the virus in midtown Manhattan, unless $100 million is placed on the spy's account.
   
   
5. A nephew of a recently deceased rich eccentric finds out that his uncle willed to him a treasure that he had buried on a deserted island. The nephew's unscrupulous cousin offers him a deal: either he shares the inheritance, or the cousin sells the information to a band of thieves who will surely beat the nephew to the treasure.
   
   
6. A sleazy private detective has a specialty of obtaining "evidence" in divorce cases by sending his pretty secretary to seduce the husband.
   
   
7. A professional blackmailer makes a living by using high-tech equipment to pry into the private lives of the rich and famous and threaten to publicize the things they would rather not have anyone know.
   
   
8. A priest plans to leak his penitent's confessions to the press, unless the latter deposits a substantial sum of money on the priest's account.
   
   
9. A fan copies the highly embarrassing personal diary of a famous novelist and demands that the novelist marry her or else she auctions the diary on eBay.

In what sense is it "unjust" to outlaw blackmail in any or all of these scenarios?

February 17, 2002