Since several years there is an ongoing dispute in Germany regarding the question how the contractual position of authors and performers could be improved. This situation caused a fundamental reform of copyright contract law in 2002. The author shows that this reform did not have the expected effects. Therefore authors started to reuse a remedy which seemed to be forgotten since years, namely: a group action against general terms and conditions (GTC). For the first time this work comprehensively explores all the legal issues of a group action against GTC in copyright contract law. The author considers the procedural specifics of group actions, in particular if associations of authors forward a claim against rightholder's GTC. He discusses the legal effectiveness of typical clauses. Thereby the author examines, which rules of German copyright law could be used as a guiding principle for the control of GTC. Special consideration is paid to the popular buy-out-clauses and the case law of German Federal Surpreme Court. The author's analysis provides important input for a new reform of copyright contract law in Germany and Europe.