A vast and contentious network of facial recognition cameras keeping watch over Moscow is now playing a key role in the battle against the spread of the coronavirus in Russia.
The city rolled out the technology just before the epidemic reached Russia, ignoring protests and legal complaints over sophisticated state surveillance.
Since last month, thousands of Muscovites have been confined to their homes for 14 days of compulsory quarantine after returning from virus-hit countries, being in contact with those infected or diagnosed with mild symptoms.
Police have logged their details and warned them that sneaking out into the city of 16 million residents and daily visitors could lead to a five-year jail term or deportation for foreigners.
"We are constantly checking that this regulation is being observed, including through the use of automated facial recognition systems," Mayor Sergei Sobyanin wrote in his blog in February.
The Russian capital already had a tight network of 170,000 security cameras, set up in streets and metro stations throughout the city over the past decade.
Around 100,000 have now been linked to artificial intelligence systems that can identify people being filmed. The remaining cameras are due to be connected soon.
Moscow police said last week that the cameras that are linked have allowed them to identify almost 200 people who broke quarantine rules.
As well as the cameras, Russia has said it is drawing on an array of technology to fight the virus, including telemedicine consultations, the real-time monitoring of supermarket shelves and identifying and removing
false news stories from social media.
President Vladimir Putin last week toured a hi-tech centre set up to monitor the virus situation and Russia's response.
The country, as of Monday, had reported 438 coronavirus infections, most of them in Moscow. One person who was infected has died but officials are not linking the death to the virus.
Moscow City Hall has boasted that the network of cameras is a particularly effective tool.
Sobyanin has said that the authorities have contacts and work addresses for 95 percent of those quarantined after returning from high-risk countries.
"We've identified where they are," said the mayor, who heads a working group on combatting the virus set up by Putin.
Last month on his blog he praised the efficiency of the facial recognition system with a story of a Chinese woman who tested positive soon after arrival and was hospitalised.
Her flatmate was quarantined but security cameras filmed her walking outside and meeting a male friend.
The mayor added that the authorities swiftly gathered contacts of more than 600 of the woman's neighbours and even her taxi driver from the airport.
Facial recognition technology was first tested during the 2018 World Cup in Russia before going fully online in January, just before the pandemic hit.
"The probability of a mistake by our facial recognition algorithm is 1 in 15 million," said Alexander Minin, CEO of NtechLab, the company that won the city's tender to supply the technology.