BIS is short for Bundesamt für Innere Sicherheit (Federal Office for Internal Security). Unlike the BKA, which shares some of its responsibilities, the BIS is a secret service rather than a police force. This German authority deals with terrorism, counter-espionage, treason, organized crime and also megacorporate activities. The BIS also monitors the German state governments and their loyalty to the Federal Government in Hannover.
Work is done mostly by highly trained undercover operatives but in times of need the elite armed forces of the Bundesgrenzschutz (or any other police) can be requested. BIS does have its own team of Matrix commandos known as Einheit 13 (“Unit 13”).