These people, according to some of the procurement documents, included those with mental illness, convicted criminals, fugitives, drug users, petitioners, suspected terrorists, political agitators and threats to social stability. Other systems targeted migrant workers, idle youths (teenagers without school or a job), ethnic minorities, foreigners and those infected with H.I.V.
The authorities decide who goes on the lists, and there is often no process to notify people when they do. Once individuals are in a database, they are rarely removed, said experts, who worried that the new technologies reinforce disparities within China, imposing surveillance on the least fortunate parts of its population.
In many cases the software goes further than simply targeting a population, allowing the authorities to set up digital tripwires that indicate a possible threat. In one Megvii presentation detailing a rival product by Yitu, the system’s interface allowed the police to devise their own early warnings.
With a simple fill-in-the-blank menu, the police can base alarms on specific parameters, including where a blacklisted person appears, when the person moves around, whether he or she meets with other blacklisted people and the frequency of certain activities. The police could set the system to send a warning each time two people with a history of drug use check into the same hotel or when four people with a history of protest enter the same park.
Yitu did not respond to emailed requests for comment.