1875 Totten Doctrine, the tool the CIA uses to cheat agents.
After the Civil War, the administrator of the estate of an alleged spy for the United States Government sued for
breach of a secret contract that the deceased, William Lloyd, claimed to have entered with Abraham Lincoln for
espionage services.
The Supreme Court, in dismissing the claim, established the Totten Doctrine, which states that courts do not have jurisdiction to consider claims related to secret contracts since review of the alleged contract would both compromise intelligence operations and embarrass the US Government.
In Totten, the Supreme Court took issue not with the ability of the President to enter into secret contracts, but with claims brought on the basis of secret contracts. Judicial review of secret contracts for secret services would needlessly endanger national security. Furthermore, bringing such a claim would constitute unclean hands and the government could be embarrassed.

