Building a national system of social governance (guojia zhili tixi), which is the long-running governance dream of Xi Jinping, has triggered the creation of China’s ‘smart state’ using the tools of new information technologies to advance governance capacity (zhili nengli). These systems were already deployed nationally when the COVID-19 pandemic hit China, but were connected at a lesser capacity, targeting specific domains of security, industry or government administration. In response to the crisis, multiple technologies have been merged, exceeding the scope of their originally intended functions. This is known as function creep, when surveillant technologies remain functional past achievement of their intended purpose, or surveillant assemblages, where multiple surveillant technologies are combined. As more countries turn to digitalisation to increase public security and intensify social and market governance, the expansion of surveillant functions in China and their now-palpable effects on people’s lives raises new and pressing questions for scholars and decision-makers alike.