The outbreak of Covid-19 has been anathema for most of China's economy but the novel coronavirus was a shot in the arm for the state's surveillance apparatus, which has expanded rapidly in pursuit of the epidemic's spread. Facial recognition cameras, phone tracking technology and voluntary registrations have all been deployed to monitor the flow of people and the possible transmission of disease. The Chinese surveillance systems currently ... has two purposes: the first is to monitor public health and the second is to maintain political control," says Francis Lee, a professor ... at the Chinese University of Hong Kong. Once the outbreak is controlled, however, it's unclear whether the government will retract its new powers. While facial recognition provides a way to monitor crowds from a distance, governments have deployed close-range means of tracking individuals too. The municipal government of Hangzhou worked with ecommerce giant Alibaba to launch a feature through the company's mobile wallet app, AliPay, that assesses the user's risk of infection. The app generates a QR code. Guards at checkpoints in residential buildings and elsewhere can then scan that code to gain details about the user. John Bacon-Shone ... at Hong Kong University thinks that the ongoing threat of outbreaks will provide a constant justification for the new systems. "I am rather pessimistic that there will be full rollback of data collection once it has been implemented," Bacon-Shone says.