“In the era of big data and the internet, the flow of each person can be seen clearly,” epidemiologist Li Lanjuan told state broadcaster CCTV during an interview in February.

The renowned scientist compared China’s response to Covid-19 with its reaction to Severe Acute Respiratory Syndrome (SARS), alluding to technological developments that make it easier to track citizens.

“We should make full use of technologies such as these to find and contain the source of infection,” she said.

Epidemic control is a big data problem. Effective management requires officials to find out who has the disease, identify people they have met, and contain those affected to prevent further transmissions. The less the government knows, the more it has to restrict everyday life to stop the spread of disease.

As the infection began to spread, so did panic. And people’s data became collateral damage.

In its fight with the virus, China is collecting unprecedented amounts of data to keep the highly transmissible virus under control. While these efforts were largely improvised during the first few weeks of the outbreak, the surveillance systems are now harvesting personal data with increasing efficiency. 

“It is clear that they are collecting very sensitive data, and that they are storing it in databases in several different places, all potentially vulnerable,” Lokman Tsui, assistant professor of journalism at the Chinese University of Hong Kong, told TechNode.

Crude but effective

Even in the world’s most digital society, the flu-like virus ran rings around sophisticated surveillance systems. At the beginning of the outbreak, the heavy lifting was done by hand.

In Hubei, the province at the center of the epidemic, health authorities demanded that pharmacies and medical centers report the names, addresses, and ID numbers of people who bought fever and cough medicines after Jan. 20, three days before the province’s capital was locked down. The initiative was an effort to find unreported infections.

As transmissions around the country soared, and existing surveillance mechanisms proved ineffective, the state did the only thing it knew would work: cut off transportation routes and relegate people to their homes. 

On Jan. 23, the most extensive quarantine in history was put into effect. Residents of Wuhan, the city at the center of the outbreak, woke to the news that the metropolis of 11 million people had been locked down. No one was allowed out of the city. Trains and flights were canceled. Public transport was shut down.

The cordon sanitaire quickly expanded to include the whole of Hubei—a province of more than 50 million people. Zhejiang, on China’s east coast, later imposed similar measures, along with dozens of villages across the country. What travel was allowed was governed by paper administration. As the outbreak accelerated, officials required travelers to put pen to paper to detail their recent travel history and health status.

Cities around the country demanded residents returning home during the Lunar New Year holiday register their details with authorities in a bid to track down and isolate people who had been to Hubei. Meanwhile, train stations began handing out paper health declarations as millions made trips home to see their loved ones.

The system quickly showed holes. As the infection began to spread, so did panic. And people’s data became collateral damage. Hubei residents found their phone and ID numbers, home addresses, and travel itineraries circulating in chat groups on popular messaging app WeChat. Local officials appear to have leaked the data, and the information spread like wildfire.

China’s telecom providers stepped in, showing the extent to which they can track subscribers.

Those affected took to social media to implore others to stop disseminating their data. “It is illegal to disclose personal information, which seriously violates our legal rights and threatens our personal safety,” one person said on microblogging platform Weibo.

But the damage was done, and people with a connection to Hubei quickly became pariahs in their communities. A number of the people affected by the leaks reported being harassed by phone and WeChat by unknown individuals demanding they “immediately isolate” themselves even if they had shown no symptoms after the 14-day incubation period.

Ten days later, China’s internet watchdog reiterated data collection rules: No using personal information collected to control the epidemic for other purposes. No collecting data from people who aren’t suspected of being infected or who have been diagnosed. No organizations other than those authorized by the National Health Commission were to use Covid-19 as a reason to collect personal data without permission.

Digital experiments

After extending the Lunar New Year holiday by more than a week, officials wanted to get people back to work. They needed systems that could filter low and high-risk people. The first solutions used travel histories as a proxy for infection risk; most cities’ rules deemed people safe if they hadn’t moved around the county for two weeks.

China’s telecom providers stepped in, showing the extent to which they can track subscribers. China Mobile, China Telecom, and China Unicom all launched services on Feb. 13 that allow users to get a report of where they have traveled in the previous two weeks based on cell phone tracking.

Users could request an itinerary by SMS listing areas they had visited in the previous two weeks, giving them a way to prove to checkpoint guards they had not visited the worst-affected areas.

It’s unclear how widely and effectively these itineraries are used. When testing the feature shortly after it was rolled out, TechNode found that not all movements between cities were recorded. A correspondent who traveled between Shanghai, Beijing, and Shenzhen over two days found that China Mobile’s system recorded only Shanghai in their itinerary. 

Cities also outsourced their health surveillance efforts to employers. In Shanghai, where TechNode’s headquarters are based, the government required companies to collect health information from their employees daily. These firms need to store all their workers’ data. If someone is suspected of infection, their information is handed to authorities.

The aim is simple: To track people’s mobility and regulate their movements based on an assessment of their potential Covid-19 infection risk.

Meanwhile, residential communities began recording information from people arriving and leaving their premises while implementing temperature screening at their gates. Notices appeared on apartment doors requesting those who had been to Hubei report to local authorities and quarantine themselves for two weeks.

Cities also began implementing real-name registration to track the movement of people on local public transport systems. The system is typically used to link online accounts to individual identities, allowing actions to be digitized, categorized, and tracked.

With the help of China’s tech giants, several cities across the country, including southern China’s Shenzhen and the eastern Chinese city of Ningbo, rolled out platforms requiring commuters to register when using the subway, bus systems, and taxis. Passengers scan a QR code that logs their movements and allows the government to identify anyone who has come in contact with someone suspected of being infected.

But paperwork was still a big part of the system, with paper passes controlling access to apartment buildings.

Then, as lockdowns expanded, the eastern Chinese city of Hangzhou, 750 kilometers away from the center of the outbreak and home to Alibaba, began hatching a controversial new plan to digitize these passes and replace full-scale lockdowns with targeted quarantines.

QR-code quarantines

Zhejiang province, the second worst-affected area in China, began cutting its cities off from the outside world on Feb. 2, ten days after Wuhan. Soon, just one member of a household was able to leave their apartment every two days.

Working with the government, Alibaba’s fintech affiliate Ant Financial and social media giant Tencent rolled out digital quarantine platforms to alleviate the situation. The systems assign users a rating based on their health status and travel history. Cities are not required to adopt the platforms. Still, Alibaba says they are being used in more than 200 cities across China, effectively functioning as health passports.

The result of the combination of these platforms is a patchwork of systems with different purposes and run by various organizations.

The aim is simple: To track people’s mobility and regulate their movements based on an assessment of their potential Covid-19 infection risk. Users need to self-report their health status, including whether they have any symptoms associated with the virus that has killed nearly 3,300 people in China. 

The result is a pass that dictates whether people are free to move around the cities in which they live, or confine themselves to their homes for a specified amount of time. A red pass requires its holder to quarantine themselves at home for 14 days while those rated yellow need to isolate themselves for a week. People with green codes can travel freely, scanning QR codes at residential compounds and supermarkets to track where they have been and update their color pass if needed.

People in Hangzhou were quick to adopt the QR code system, and a broad lockdown of the city was replaced with targeted quarantines.

Alipay’s system is going national, and cities around the country have started accepting health passports issued in other provinces, partially normalizing travel between many cities. But TechNode’s reporting also found significant regional variations in how the system is implemented. In Beijing, for instance, paper passes still take precedence over the health passport platforms. In Shanghai, QR codes are rarely inspected, and checkpoints do not appear to scan codes to generate further data for the system.

Read more: How China is using QR code apps to contain Covid-19

Tencent said during an earnings call last week that its system is currently used by 900 million people in 300 cities across China. “Health Code has become the most used ePass for verifying health and travel history during the outbreak,” said Martin Lau, the company’s executive director and president. 

While health data and travel histories are used to drive the QR code system, it is unclear what other types of information are being fed in and used for surveillance. This haziness is causing people to change their behavior. 

Across the country, people need to provide identifying information when purchasing such medicine online. Transactions made through delivery services Meituan and Ele.me prompt buyers to provide their ID details if the medication can be used to treat a cough or fever, according to a TechNode investigation. 

“We will do our best to protect your personal information security,” reads a disclaimer in Meituan’s app when paying for such medicines. The company says it is required to report the information to epidemic prevention and control authorities.

Meanwhile, many people have avoided using shared bikes following rumors that the data may be shared with the health passports, causing them to change color if they bike near a known case of the virus.

Who has the data?

The result of the combination of these platforms is a patchwork of systems with different purposes and run by various organizations, in which users have little visibility into how data is transmitted, analyzed, and stored. There is no clarity over who developed the algorithms that drive these platforms nor how they work, but also little appeal for those who find themselves disadvantaged.

In March last year, Dutch researchers found an online trove of 364 million social media records.

In a statement to TechNode, an Alibaba spokesperson said that the company acts only as a conduit for health passports, providing a platform for local governments, which run the systems and control users’ data. The company denied having any access to users’ information.

Still, the close relations between the government and a private company have made some uneasy.

“I’m very much against this combination of government and enterprise control of big data,” said one Weibo user of the health passport system. “I’ve been sitting at home for so long that I had to give in [and register],” they added.

Others said that the measures are reminiscent of “The Truman Show,” a 1998 film in which a man’s life is carefully tracked, scrutinized, and broadcast on television.

In addition to these concerns, several high profile data leaks from government-backed surveillance programs over the past year highlight a danger to China’s population.

In March last year, Dutch researchers found an online trove of 364 million social media records that had been mined from WeChat, QQ, and e-commerce giant Taobao’s merchant-customer communications system Wangwang. The data was unsecured and accessible to anyone with a little know-how.

The operation targeted China’s internet cafe users, who are required to register their identities when using such services. The surveillance system collected identity numbers, chat logs, and locations, and sent these details to the police, the researchers said.

In another case, the same researchers found an unsecured database containing the ID and location data of more than 2.5 million people in the northwestern province of Xinjiang. The surveillance database belonged to Sensenets Technology, a Shenzhen-based facial recognition company that has worked with Chinese police in several cities around China.

In China, privacy protection is primarily focused on keeping other companies from accessing the data, not the government, Martin Chorzempa, research fellow at Washington-based think tank the Peterson Institute of International Economics, told TechNode.

“A lot of thinking needs to be done on how this information is shared with local officials while preventing them from unauthorized sharing,” he said.

Increasingly strict data protection regulations require companies to ensure that sensitive personal data remains secure while granting the government access to users’ information should they request it.

Will it ever end?

There are indications that the health passport system could survive the epidemic. An expert quoted by Chengdu Business Daily said he expects health passports to “increase the efficiency and lower costs of healthcare services” even after the outbreak wanes.

According to Patrick Poon, a Hong Kong-based researcher at Amnesty International, the increased data collection and surveillance amid the outbreak sacrifices people’s rights to privacy “for the sake of public health,” adding that the crisis could have been handled better if the government had been more transparent. 

Poon highlighted how doctors working in Wuhan who shared information on WeChat in December about a “Sars-like” disease that was beginning to sweep the city were quickly reprimanded and silenced. One such doctor, Li Wenliang, died of the disease on Feb. 6. 

“The government will definitely use this as an excuse to enhance surveillance,” said Poon.

Meanwhile, netizens are also worried: “After the outbreak, will the collection of personal information continue?” asked one Weibo user. Several others shared similar concerns.

“In China, that is not an unlikely outcome given its history and culture of surveillance,” said CUHK’s Tsui.

Wide-ranging QR code surveillance will be challenging to implement long term. The tracking process is far from automated, and to get people to scan ubiquitous codes, cities have had to set up checkpoints and deploy legions of guards. Not all cities that have QR codes have made this investment. And even in those that have, enforcement fell off quickly.

Regardless, governments see their response as a vindication of surveillance, and the experience could drive further investments in automated systems.

Christopher Udemans is TechNode's former Shanghai-based data and graphics reporter. He covered Chinese artificial intelligence, mobility, cleantech, and cybersecurity.