__NOTOC__ A black room is part of a communication center (e.g. a post office) used by state officials to conduct clandestine interception and

surveillance Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing or directing. This can include observation from a distance by means of electronic equipment, such as c ...

of communications. Typically, all letters or communications pass through the black room before being passed to the recipient. This practice had been in vogue since the establishment of postal and telegraph services, and was frequently used in France by the ministers of Louis XVIII and his followers as the ''

cabinet noir In France, the ''cabinet noir'' (French for " black room", also known as the "dark chamber" or " black chamber") was a government intelligence-gathering office, usually within a postal service, where correspondence between persons or entities wa ...

'' (French for "black room"). In modern American network operations centers, optical splitters divert a percentage of the laser light from all incoming and outgoing fiber-optic cables to the secret room. An example is Room 641A in the

SBC Communications The history of AT&T dates back to the invention of the telephone. The Bell Telephone Company was established in 1877 by Alexander Graham Bell, who obtained the first US patent for the telephone, and his father-in-law, Gardiner Greene Hubbard. Bell ...

building in San Francisco. The term ''black room'' or '' black chamber'' has also been used to refer to any place or organisation dedicated to code-breaking.

References

{{reflist Privacy of telecommunications Postal systems Black room

See also

References