This woman is being scolded for being outside without a face mask and was chased back into her home.

(Speaking Chinese) Those playing cards down there, please disperse now.

These people are being admonished for hanging out in a group.

They were all caught by Chinese authorities who have been deploying drones equipped with high-resolution cameras and loudspeakers.

(Speaking Chinese) Don't go out and party.

It's one part of China's massive surveillance strategy to tackle the spread of the coronavirus, which has reached just about every region in the country.

The virus has infected more than 80,000 in China, resulting in the deaths of more than 2,000 people in the country, far surpassing the death toll from SARS.

The difference between 2003 and 2020, you know, is really enormous in terms of the government's reliance on and development of surveillance technology.

Almost none of these tools were on offer at that time.

Sophie Richardson is the China Director at Human Rights Watch.

She says during this public health crisis, China is embarking on an unprecedented use of surveillance by using big data and its citizens.

So what exactly is China's surveillance strategy and can it work to battle the epidemic?

(Speaking Chinese) This auntie possibly isn't wearing a mask.

There are an estimated more than 300 million surveillance cameras in China and authorities are using them to monitor Chinese citizens.

Many of the surveillance cameras in use in China now are equipped with facial recognition capabilities which simply gives the authorities the ability to track who specifically has gone to which precise location.

Combine that with data scraped from hospital records, police files, and public transportation history.

All that is stored and linked to national ID cards, which gives the Chinese government granular information about all its citizens.

In January, a man who tested positive for the coronavirus used public buses and subways to crisscross China's eastern city of Nanjing.

The police posted his journey with specific dates and times on social media with a warning that anyone who was in that area get tested for the virus.

China's public health authorities have been candid about the use of big data during this public health crisis.

(Speaking Chinese) Big data can tell you if someone around you may come from the epicenter or if someone is infected.

They even developed a mobile phone app called the Close Contact Detector.

The app has a database of people who have tested positive or have symptoms, so as soon as you type in your name and national ID and log in, the app will tell you if you've ever come into close contact with someone who tested positive or if you're in the clear.

So far, more than 200 million people have used the app.

These new and different uses of technology around the coronavirus may help resolve some of the public health concerns, but it's also another way for the government to gather large amounts of information about people, really, effectively without their consent and, in some cases, without even their knowledge.

Chinese health officials say all this data is in the pursuit of controlling the epidemic.

(Speaking Chinese) We can get a clearer picture of the spread of the epidemic, and then we can also offer suggestions and guidance to the related departments especially those at community levels.

In China, many people probably have not developed that kind of awareness in terms of protecting their privacy, protecting their civil liberties.

Yanzhong Huang studies global health at the Council on Foreign Relations in the U.S.

He says many in China want this type of monitoring because it's about life or death.

And when they were given the choices of protecting their health and protecting their civil liberties, you know, [they] probably would choose the former even to the detriment of the latter.

Huang says increasing population control during a health crisis can be a slippery slope.

This widespread use of surveillance technologies may also encourage the use of the same technologies, surveillance techniques even after they operate, you know, for purposes [that] may not be really justifiable.

People are also a big part of its surveillance apparatus.

After all, President Xi Jinping said the fight against the virus was a people's war.

Authorities send out text messages telling people to go directly to authorities if they come from Hubei Province where the coronavirus first emerged, and announcements are posted all around town encouraging everyone to monitor each other.

(Speaking Chinese) I will give you a mask.

Police patrol streets telling people without face masks to go home.

Some managers of apartment complexes go door to door to check on residents' health conditions.

This may sort of suggest that this is a revival of the Cultural Revolution era, when you saw there's people monitoring their neighbors, you know, or even their relatives.

Some provinces have started giving an incentive to monitor family members' travel histories and health.

(Speaking Chinese) Report if you know anything.

(Speaking Chinese) This can help others get informed earlier.

(Speaking Chinese) It is for your own good to cut loose from your relatives.

(Speaking Chinese) Reward!

In Sichuan Province in western China, snitching can snag you as much as 5,000 yuan.

That's roughly equivalent to a monthly salary that's more than minimum wage.

One government in Guangdong Province is offering 30 face masks in exchange for snitch reports.

During this public health crisis, China hasn't been the only country to use technology to track patients.

In South Korea, health authorities are legally allowed to sift through credit card records, CCTV footage, and mobile phone locations to pin down the travel histories of those infected or at risk.

That information is then shared with the public.

In China's surveillance state, not only do authorities have access to more data than other governments, but citizens have no way to opt out of that data collection.

Beijing says all this is in the best interest of the public.

We'll have to be able to see how the virus ultimately played out, who was affected, who wasn't... whether the surveillance technology helped.