The hybridization of regulatory modes and instruments is currently a popular way to improve public regulation. However, it is still unclear whether combinations of hard law and soft law, co-regulation, and legally enforced self-regulation really make regulation more effective. Using the analytical framework of the “really responsive regulation” approach, in this article we explore effectiveness problems in a hybrid regulatory system that tries to protect minors from harmful media. In our analysis of low compliance rates in the context of system failures, we argue that effectiveness problems seem to arise from poorly informed staff members, lack of internal and external controls, low rule enforcement, insufficient overlap between public and private interests, poor social responsibility in the Dutch media sector, deficiencies in the institutional framework, an inconsistent regulatory strategy, and inadequate responses from responsible regulators. Furthermore, based on our case study we argue that institutional dynamics of standard-setting activities can be detrimental to regulatory goal achievement if there is no compensation at the systemic level. Ongoing “regulatory care” through control, corrective responses, and rule enforcement seems to be crucial for a hybrid regulatory system to perform well.