To justify surveillance measures and gain them public support, governments use the promise of security. It is usually claimed that individuals are more willing to have freedom and privacy restricted than waiving a promise of increased security. However, empirical evidence to support this claim has been scarce—especially from a comparative perspective. Focusing on surveillance measures, this paper shows that people do indeed express greater acceptance of restrictions when these are justified by promises of security, being one of the first to examine this across 29 countries on all continents. Based on data from the ISSP, it investigates to which degree the effect of a security-based justification is moderated on the micro and macro level, with surprising results: While the effect does not differ between different levels of government support and political orientation, it differs significantly depending on how liberal-democratic the country is. The effect of the security-justification is very pronounced in liberal democracies, while it is even reversed in rather autocratic countries, meaning that individuals seem to be rather suspicious towards security justifications in non-democratic countries.