Today, Facebook and co. control more and more aspects of everyday life and the economy. Their data-driven business models pose new challenges, especially for competition law. Against this background, the book examines the interplay of competition and data protection law in a European context and aims to show whether the chronic data protection violations by the big players of the digital economy can also be dealt with under European competition law. The main focus of the work is to examine if and how data protection principles can be taken into account when applying Art. 102 TFEU and what alternative solutions to the competition law regulation of Facebook and co. exist.