Cabinet noir

[1] However, this had to be done with some sophistication, as it was considered undesirable if the subjects of the practice knew about it, and important "that the black chamber not interrupt the smooth running of the postal service.

A black chamber was also employed by Anthonie Heinsius, Grand pensionary of the Dutch Republic, during the War of the Spanish Succession under the direction of his private secretary Abel Tassin d'Alonne.

[6] In 1911, the Encyclopædia Britannica Eleventh Edition took the view that the cabinet noir had disappeared, but that the right to open letters in cases of emergency still appeared to be retained by the French government; and a similar right was occasionally exercised in England under the direction of a Secretary of State.

Whatever the justification, this meant that not a single letter sent from a soldier to his family escaped previous reading by a government official, destroying any notion of privacy or secrecy of correspondence.

[7] The US Trade Act of 2002 permits the opening of international mail to and from the United States by Customs[8] under the border search exception to the Fourth Amendment of the Constitution.