"The machine," an advanced computer system featured in the American television drama Person of Interest that is able to use closed circuit television (CCTV) cameras to predict crimes, may not be so far fetched after all. A video that went viral on Chinese social media recently offered a glimpse into just how far China's cutting-edge surveillance technology has come.

In the video, footage taken by CCTV cameras is instantly tagged with information of passing vehicles and pedestrians, including each person's sex, age and clothing and the model and color of cars. Tags appear on each person and vehicle as soon as they enter the camera's range.

The system is also able to scan faces and compare them with its database of criminal suspects at large. When there is a match, an alarm notifies the police of its findings.

Resembling Minority Report or some other sci-fi movie, this cutting-edge surveillance technology is from a new system developed by SenseTime, a Chinese technology company headquartered in Beijing.

Equipped with 20 million CCTV cameras, China now has the largest monitoring network in the world, according to Amazing China, a six-episode documentary co-produced by the Publicity Department of the Communist Party of China (CPC) Central Committee and China Central Television (whose acronym is also, coincidentally, CCTV).

The network, dubbed "Skynet" (a name taken from the fictional net-based artificial intelligence in the futuristic Terminator films), aims to boost public security as personal and societal safety threats increase across the world.

Operation Skynet

Wang Qiang, a specialist in non-war military actions at the National Defense University of the People's Liberation Army, defines the Skynet system as an infrastructure based on artificial intelligence and big data that aims to boost public safety. "CCTV cameras are like eyes that protects people's safety," he said.

Since it was launched in 2011, many Chinese cities have been stepping up their effort to deploy more CCTV cameras.

From 2011 to 2015, the government of Changsha, Hunan Province, invested 528 million yuan ($35.39 million) in the Skynet project, installing over 50,000 CCTV cameras. At least 27,000 of them are high-definition, capable of capturing footage at night using infrared lenses, according to news portal rednet.cn. The government of Nanchang, Jiangxi Province, had deployed 35,000 CCTV cameras in the city by 2016, with over half being high-definition.

The sheer number of new CCTV cameras, however, may not be enough. In 2015, Chinese regulators issued a document on the strengthening of its surveillance camera network, aiming to boost public safety, optimize traffic and serve city management.

According to the document, by 2020 China will build a surveillance network that achieves full coverage in key locations, connected to the Internet and with a serviceability rate at over 95 percent in major public areas. The network will also feature an internal security system, preventing sensitive footage from being hacked or stolen.

Amazing China features a scene at the big data center in the public security bureau in Suzhou, East China's Jiangsu Province, where a large screen exhibits hundreds of scenes captured by CCTV cameras in the city - all in real time.

"CCTV camera coverage on the roads is already very high. If a crime happens, we are capable of zooming into a certain spot on the suspect's body, according to our needs," said Zhong Cong, a police officer at the bureau whose responsibility is to analyze and predict crimes based on this footage.

"Criminals will have nowhere to hide thanks to the three-dimensional public security protection system," he added.

Apart from the cameras, Suzhou police are also able to predict crimes through big data such as each household's consumption of water and electricity. When anomalies occur, the system will send alarms, according to the documentary.

A big data system on the consumption of fertilizer and petroleum, has also been deployed in Xinjiang Uyghur Autonomous Region to alert public security authorities of possible crimes, South Magazine reported earlier. Ammonium nitrate fertilizers, when combined with other reagents, can become a powerful explosive.

No privacy infringement

Statistics show that Skynet has achieved huge successes since it was systematically deployed in 2011, helping decrease the overall crime rate in China.

In the first 8 months in 2016, police in Nanchang arrested 1,600 criminal suspects, solved nearly 3,000 cases and captured images of 90,000 vehicles that violated traffic regulations through the help of Skynet. In the three years since Skynet was deployed in Changsha, police solved over 17,000 cases using Skynet, including murders and robberies.

According to Xinhua, the crime rate for eight types of felonies including drug trafficking, robbery and intentional injury in China dropped 42.7 percent between 2012 to 2016. Over 90 percent of the Chinese population now say they feel safe.

SenseFace's facial recognition system is currently being used by public security authorities in Beijing, Chongqing and other provinces including Guangdong, Sichuan and Hainan, playing an important role in daily monitoring and solving crime cases.

Xu Li, CEO of the company, told thepaper.cn that when the system was first tested in Chongqing, it identified 69 criminal suspects in 40 days. Fifteen of these suspects were later arrested and detained by the police.

The system can also tell the difference between motor vehicles and non-motor vehicles and distinguish between 3800 car models with a 95 percent accuracy rate.

But as China's surveillance network becomes more powerful and all-seeing, some privacy advocates have been questioning whether the system will infringe on personal privacy.

Wang addressed this by saying that, according to Chinese law, public surveillance cameras should be clearly marked. It is also prohibited to install them in private places such as hotel rooms, dormitories or public restrooms.

"These regulations will safeguard people's rights and serve as the legal basis for Skynet," he said.

Lower tier, less cameras

Legal experts confirmed that it is completely legal for the police to use Skynet to collect footage.

Xue Jun, professor of law in Peking University, told China News Service that as the footage collected by Skynet are in public areas, people's privacy isn't infringed according to Chinese law.

Xu Kai, a Beijing-based lawyer, said that people's personal information is a right, but also an obligation. When required by law, they must hand everything in to the government.

"However, if this footage is used without authorization or used for purposes other than official crime investigations, there are possibilities of infringement," Xu said.

And while the scale of its surveillance network is the biggest in the world, compared with its massive population, China still lags behind developed countries in its deployment of surveillance cameras. For every 1,000 citizens in Beijing (China's most closely-monitored city), for example, there are 59 surveillance cameras, according to statistics released at the 2016 Beijing International Intelligent Hardware Exhibition. This means there is one surveillance camera for every 17 people in Beijing.

In China's second- and third-tier cities, however, the density of CCTV cameras is much lower, estimated at under one per 100 people on average.

In the UK, numbers are estimated at one camera per 14 people and in the US, one for every 10. The British Security Industry Authority estimated in 2013 that there are up to 5.9 million closed-circuit television cameras in the country, including 750,000 in "sensitive locations" such as schools, hospitals and care homes, according to the Telegraph.

Experts in the surveillance hardware industry predict more surveillance in the years to come. In 2015, China's video surveillance market was estimated at 74 billion yuan, with the market projected to grow 10 percent each year.