The boundaries of privacy: Covert intelligence gathering, rule of law, and human rights in comparative perspective

This article examines covert intelligence-gathering frameworks in six jurisdictions - Hungary, Austria, Croatia, France, the United States, and China - alongside a case study of Serbia's 2024 reform, testing a 'modernity paradox': the proposition that technological sophistication in surveillance regulation does not correlate with stronger rule-of-law protections. Using a qualitative, most-different-systems comparative design structured around three analytical domains - authorization mechanisms, technological capabilities, and human rights risk - the study develops a 'classical-adaptive-modern' typology. Particular attention is devoted to the tripartite structure of Hungarian covert intelligence law - the Nbtv. (Nemzetbiztonsági szolgálatokról szóló törvény / Act on National Security Services), Rtv. (Rendőrségről szóló törvény / Police Act), and Be. (Büntetőeljárásról szóló törvény / Code of Criminal Procedure) tracks - the historical TIGY (titkos információgyűjtés / covert intelligence gathering) / TASZ (titkos adatszerzés / covert data acquisition) dichotomy abolished by the 2017 codification, covert-detection provisions in sectoral statutes beyond the Nbtv. and Rtv., and the implications of the 2025 targeted legislative amendments. Findings confirm a structural inverse relationship: Croatia (classical) combines conservative tools with robust parliamentary oversight, while the United States and China (modern) combine extensive collection capacities with the weakest authorization regimes. Hungary, Austria, and France (adaptive) exhibit recurrent 'grey zones' where new capabilities outpace existing safeguards. Serbia's 2024 reform illustrates that typological classification represents a policy choice rather than a fixed destiny.