The appearance of a secret control of any type of connection is always associated with the birth of this type of connection. So, unauthorized tapping of telephone conversations began along with telephone communications. The book tells the story of the birth and development of special services engaged in wiretapping in Europe, the USA, the Russian Empire, the USSR and the Russian Federation | creation and evolution of special equipment by the operational and technical services of these countries to control telecommunications | describes the most important special operations to intercept information and wiretap communications.