Moscow is the latest major city to introduce live facial recognition cameras to its streets, with Mayor Sergei Sobyanin announcing that the technology is operating “on a mass scale” earlier this month, according to a report from Russian business paper Vedomosti.

It follows news earlier this week that London is integrating live facial recognition into daily police activities, with the Metropolitan Police deploying cameras in busy tourist and shopping areas to spot individuals “wanted for serious and violent offences.”

Privacy campaigners say the technology turns public spaces into “virtual identity parades”

Facial recognition has been used by police for years to identify individuals in archive footage, but the deployment of live facial recognition systems is a new development. It lets law enforcement identify individuals in a crowd in real time, but privacy campaigners say it erodes civil liberties, turning anonymous public spaces into “virtual identity parades.”

Moscow started trialing live facial recognition in 2017, using technology from Russian firm NtechLab to scan footage from the Russian capital’s network of 160,000 CCTV cameras. The company is best known for its FindFace software, which it launched in 2016 and let users match anyone in a picture to their profile on VK, known as Russia’s Facebook.

The app was criticized by some, particularly as it was used to dox and harass sex workers, and NtechLab eventually shut it down in favor of enterprise and government work.

The company signed a contract with Moscow’s Department of Information Technology on January 1st this year (though other vendors are involved in other parts of the system), and the news was covered by local media earlier this week, which we spotted via Forbes.

What’s not clear is the scale of this deployment. There are no official figures on how many cameras are hooked in to the technology, but NtechLab’s CEO Alex Minin told The Verge over email that the deployment was one of the biggest ever.

“We believe that the Moscow face recognition system is the largest in the world,” said Minin, adding that there may be systems that are larger that scan archive footage.

“Dedicated police officers receive alerts on their mobile phones”

According to Minin, Moscow police will use the technology by creating watchlists of suspects they can search for on live camera footage. If a match is found, the police will be notified via NtechLab’s app. “Dedicated police officers receive alerts on their mobile phones that have our FindFace Security mobile app installed,” says Minin.

The use of live facial recognition has become a controversial issue. A report earlier this year from The New York Times shed light on a company named Clearview AI, which secretly scraped 3 billion photos from social networks in order to sell facial recognition services to US law enforcement. Scientific studies have also repeatedly found that top facial recognition systems, like those sold by Amazon, display racial and gender biases.

Experts are so worried about the implications of rushing the deployment of facial recognition that many are calling for a moratorium of the technology. Even big tech companies are worried, with Google backing a temporary ban earlier this month.

NtechLab’s Minin, though, says fears about the technology are “overheated” and that companies like Clearview AI “that really do not care for privacy rights” are giving other firms a bad name.

“When carefully orchestrated, the system is not only harmless to regular people, it helps a lot in catching terrorists, criminals, pedophiles and pickpockets by aiding police to identify them in seconds and locate and capture them in hours instead of days and weeks,” says Minin. “The software itself doesn’t break any laws or do any harm.”