The paper explores different approaches to securing judicial oversight of collecting and processing of personaldata in a criminal justice system. It focuses on traffic communication and DNA data. A brief comparative overview show that the need to establish judicial oversight very much corresponds to the manner the right to privacy is conceptualised within a specific jurisdiction. On one side, the US relies heavily on the concept of reasonable expectation of privacy (privacy as secrecy, Solove). On the other side, European jurisdictions - although not uniformly - view privacy protection as an integral part of protecting one's personhood and dignity. The paper explores the clash of the two competing conceptions within US jurisdictions, particularly after the Snowden revelations. In general, the recognition of the need to provide judicial oversight is greater in jurisdictions that view privacy in the context of protecting one's personhood. In this sense, the level of procedural safeguards very much corresponds to the substantive understanding of the right to privacy