The initial court ruling in October came shortly after Twitter shut down an account used by a German neo-Nazi group based in Hanover, at the request of German police.
Researchers from the security group at Leibniz University of Hanover and the computer science department at the Philipps University of Marburg tested the most popular apps in Google's Play store.
The Sennheiser Group, with its headquarters in Wedemark near Hanover, Germany, is one of the world's leading manufacturers of microphones, headphones and wireless transmission systems.