• court of justice of the european union
• data protection
• european court of human rights
• fundamental rights
• judicial oversight
• mass surveillance
• privacy

This dissertation investigates how mass surveillance is regulated in Europe by comparing the jurisprudence of the European Court of Human Rights (ECtHR) and the Court of Justice of the European Union (CJEU). It addresses the central tension between security imperatives and the protection of fundamental rights, particularly privacy and data protection, in an evolving digital landscape. The research adopts a doctrinal and comparative method, analysing thirty-three landmark judgments — twenty from the ECtHR and thirteen from the CJEU — together with relevant academic literature. Chapter 1 lays the conceptual and legal foundations, while Chapter 2 examines the courts’ reasoning, from the ECtHR’s flexible safeguards under Article 8 ECHR to the CJEU’s categorical framework based on Articles 7 and 8 of the Charter. Chapter 3 compares these approaches, identifying convergence on principles of legality, proportionality, and independent oversight, but divergence in methodology and normative priorities. The findings suggest that although both courts increasingly influence each other, their structural differences prevent full harmonisation, leaving Europe with complementary yet distinct standards.