This study examines citizens’ support for state surveillance, contingent upon factors related to policy design and the context of implementation. While most people want to live in a secure environment, we argue in this study that the support of policies to reach this goal depends on their necessity, extensiveness and reliability. Results from survey experiments in four European countries show that citizens are ready to approve the introduction of far‐reaching state surveillance that includes measures of facial recognition and motion detection. Public support is further enhanced if these measures are to be targeted at potential criminals, rather than at all citizens (i.e., policy extensiveness), as well as if a safety threat is salient (i.e., policy necessity). Concerns about data security reduce support (i.e., policy reliability). While these conditions matter for the support of specific policies, they do not influence how trustworthy citizens consider government and other political authorities to be.