This book analyses the legal approach to personal data taken by different fields of law. An increasing number of business models in the digital economy rely on personal data as a key input. In exchange for sharing their data, online users benefit from personalized and innovative services. But companies' collection and use of personal data raise questions about privacy and fundamental rights. Moreover, given the substantial commercial and strategic value of personal data, their accumulation, control and use may raise competition concerns and negatively affect consumers. To establish a legal framework that ensures an adequate level of protection of personal data while at the same time providing an open and level playing field for businesses to develop innovative data-based services is a challenging task. With this objective in mind and against the background of the uniform rules set by the EU General Data Protection Regulation, the contributions to this book examine the significance and legal treatment of personal data in competition law, consumer protection law, general civil law and intellectual property law. Instead of providing an isolated analysis of the different areas of law, the book focuses on both synergies and tensions between the different legal fields, exploring potential ways to develop an integrated legal approach to personal data.