Bundesgerichtshof [Federal Court of Justice of Germany], First Civil Section, Jugendgefährdende Medien bei eBay, I ZR 18/04

Even if there is no direct responsibility of intermediaries due to the privilege of § 10 TMG, intermediaries have a duty to prevent others from violating youth protection law and competition law using their platform. This duty for intermediaries to interpose arises from § 3 UWG, and applies when one of his users commits a certain violation by selling goods without consideration of the protection of minors law. An intermediary has to prevent other violations from the same user by increasing observation. The intermediary must prohibit and stop transactions regarding the same product. The possible remedies include injunctions and damages.