Threema, the Swiss provider of the telephony and messaging app of the same name, was instructed by the Federal Post and Telecommunications Surveillance Service (PTSS) to monitor and unencrypt marginal data in real-time. Threema successfully appealed to the Swiss Federal Administrative Tribunal (FAT). In its ruling A-550/2019 of 19 May 2020, the FAT makes a sound statement on the concept of a telecommunications service provider.
Please find here the full article in German language.