"SDS"
Sozialistischer Deutscher Studentenbund or
German Socialist Student Union
Though unconnected to its American counterpart that shared its acronym (Students for a Democratic Society), the German SDS shared a similar place in German society. It was the leading left-wing student organization throughout the sixties (the APO -- Extraparliamentary Opposition -- was more of a movement than an organization).
Originally the SDS was the student wing of of the SPD party, but the SPD disassociated itself from SDS in 1960 when it began advocating an anti-nuclear bomb stance.