This article suggests a multi-disciplinary framework for evaluating the political and constitutional legitimacy of both traditional and new media (such as Netflix, YouTube), and explores the double function of public law: supervising the media (television, Netflix or Youtube) and their regulators. By turning to insights from political theory and social sciences, the article argues that current discourse of justifications for (any) media regulation is exposed to two main flaws: (a) Lack of rationality or social facts (due to consistent governmental bias of over-estimate the risk posed by mass media, while underestimating the their political or cultural value) and (b) Insensitivity to the hidden liberal-democratic costs of media regulation – as a cultural regulation. It then suggests how decision makers (judges, regulators, and citizens) can and should evaluate the legitimacy or desirability of various regulatory practices – present and future – in a structured, fact-based method.