Case C-280/08 P: Judgment of the Court (Second Chamber) of 14 October 2010 — Deutsche Telekom AG v European Commission, Vodafone D2 GmbH, formerly Vodafone AG & Co. KG, formerly Arcor AG & Co. KG and Others (Appeal — Competition — Article 82 EC — Markets for telecommunications services — Access to the fixed network of the incumbent operator — Wholesale charges for local loop access services to competitors — Retail charges for access services to end-users — Pricing practices of a dominant undertaking — Margin squeeze — Charges approved by the national regulatory authority — Leeway of the dominant undertaking — Attributability of the infringement — Meaning of abuse — As-efficient-competitor test — Calculation of the margin squeeze — Effects of the abuse — Amount of the fine)