Critics see China’s social credit system (SCS) as a tool of surveillance and repression. Yet opinion surveys find considerable public support for the SCS in China. We explain this puzzle by focusing on citizens’ lack of knowledge regarding the repressive nature of digital surveillance in dictatorships, which can be attributed to (1) invisible and targeted repression associated with digital surveillance and (2) government propaganda and censorship further concealing its repressive potential. A survey experiment on 750 college students in three Chinese regions shows that revealing the SCS’s repressive potential significantly reduces support for the system, but emphasizing its social-order-maintenance function does not increase support. Observational evidence from the same college survey and a nationwide survey of 2,028 Chinese netizens show that the support is higher if citizens knew about the SCS through state media. Our findings highlight the role of information and framing in shaping public opinion on digital surveillance.