§ 3 TDDDG
Confidentiality of Communications — Secrecy of Telecommunications
(1)The secrecy of telecommunications covers the content of telecommunications and the specific circumstances thereof, in particular the fact of whether a person is or was involved in a telecommunications process. The secrecy of telecommunications also extends to the specific circumstances of unsuccessful connection attempts.
(2)The following are obliged to maintain the secrecy of telecommunications. The duty of confidentiality continues even after the end of the activity by which it was established. 1 Providers of publicly accessible telecommunications services and natural and legal persons who participate in the provision of such services,; 2 providers of telecommunications services offered on a wholly or partly commercial basis and natural and legal persons who participate in the provision of such services,; 3 operators of public telecommunications networks, and; 4 operators of telecommunications installations by means of which telecommunications services are provided on a commercial basis.
(3)The persons obliged under paragraph 2 sentence 1 are prohibited from obtaining, for themselves or others, knowledge of the content or the specific circumstances of telecommunications beyond what is necessary for the provision of telecommunications services or for the operation of their telecommunications networks or their telecommunications installations, including the protection of their technical systems. They may use knowledge of facts subject to the secrecy of telecommunications only for the purpose referred to in sentence 1. The use of such knowledge for other purposes, in particular disclosure to others, is only permissible insofar as this Act or another statutory provision so provides and expressly refers to telecommunications processes. The duty to report under Section 138 of the Criminal Code shall take precedence.
(4)Where the telecommunications installation is on board a watercraft or aircraft, the duty to maintain the secrecy of telecommunications does not apply in relation to the person commanding the vessel and that person's deputy.