At a time when the European Union and its Member States are constantly adopting measures to combat serious crime and terrorism, particularly through the prism of data protection rules, the CJEU is acting as a bulwark by imposing compliance with strict conditions, thereby encroaching on national rules of criminal procedure, which are initially the responsibility of the Member States. In this contribution, we will examine how and on what basis the Ligue des Droits Humains was able to get the CJEU to rule on the Passenger Name Records Directive, and to what extent this action was indeed “strategic.”