Ubiquitous surveillance cameras, hooked into facial recognition systems. WiFi sniffers that vacuum up information from smartphones and computers. Police officers who scrutinize travel, at home and abroad.

Those are a few of the ways the Chinese government is using big data to suppress dissent and target minority groups, according to a new report by the international watchdog group Human Rights Watch. All that information ends up in databases that police and Communist Party agents use to track citizens, and their targets are often members of the Uyghur ethnic group, many of whom are Muslim and who attract disproportionate scrutiny from Chinese authorities — including, in some cases, being sent to "political education centers."

The report is noteworthy not just because of China’s mistreatment of its minority populations but because it presents a dark vision of the ways that current-day technology could be used to target vulnerable populations closer to home.

Police in some parts of the United States, for instance, are already using similar technology. A Washington Post report in 2016 detailed an LAPD program called PredPol that sent officers to areas where an algorithm believed that crimes were likely to soon take place. Chicago has used a similar program to identify — and target — individuals that a mathematical analysis deems likely to be involved in violent incidents.

Big data can be a force against intrusive surveillance. Data scientists have argued, for instance, that there is little statistical basis for the Trump administration’s travel ban from Muslim-majority countries. But the law enforcement uses for data seem to be racing ahead of the liberating ones.