What that means in practice has scared some Muscovites but comforted others.

Artyom, 30, who works in the media industry and requested his last name not be published, was of both minds.

He left his apartment building to take out the trash two days after receiving a quarantine order following a flight from Milan, he said in an interview. Two days later, police officers came to his house with an official police report and a printout showing his passport photo alongside his image taken by a surveillance camera.

“On the one hand, it’s concerning, because in the future, who knows how they could use it,” said Artyom, who now faces a court hearing and a fine, of Moscow’s facial-recognition technology. “On the other hand, if it can help them find real criminals, I think it’s a good thing.”

The Russian authorities, meanwhile, have signaled that the government’s virus-related crackdown could also affect freedom of expression. The Russian media regulator, Roskomnadzor, warned Wednesday that news outlets and websites that spread false information about the virus “will be subject to the harshest measures,” including having their licenses revoked.

Russian news outlets reported Tuesday that even tougher measures may be coming, including a lockdown and quarantine of Moscow. The city denied the reports. Russia largely closed its border to foreigners on Wednesday, its toughest travel restrictions since the fall of the Iron Curtain.

“For an authoritarian state, this coronavirus is paradise,” a Western diplomat in Moscow said, because the situation allows for the testing of tools of surveillance and control that can be used in the future to counter public unrest. “Next time you need it, just pull it out of the hat again.”