WeChat's surveillance of international users boosts censorship in China, researchers say
Citizen Lab says images, documents sent between international users train censorship algorithm
Canadian users of the popular social networking app WeChat are likely helping the Chinese company censor its users inside China, according to research from the University of Toronto's Citizen Lab.
WeChat, which allows users to send messages, interact on social networks and make digital payments, is owned by the Chinese communications company Tencent and is the most popular social networking app in China. Globally, it has more than one billion users.
Research by Citizen Lab found that documents and images sent between users with accounts registered outside China triggered censorship when those same documents and images were sent to a user inside China.
"The company is essentially undertaking political surveillance on one segment of users, those who are using their international version of the application outside of mainland China," said Ron Deibert, the director of Citizen Lab.
"That data is being used to then train the algorithms to better undertake censorship and surveillance of mainland China's users. That's pretty shocking."
Citizen Lab came to its conclusion after a series of tests over three months, from November 2019 to January 2020.
"There is a moral issue here. To the extent that you're using this application, you're also essentially providing free labour for the refinement of a machine of digital repression inside China. So you're implicated in it," said Deibert.
CBC News contacted WeChat's parent company, Tencent, through its corporate website and a public relations representative numerous times in an attempt to get a comment on the findings of the study. Tencent said it didn't have anyone available for an on-camera interview and did not respond to a request for a statement.
A day after publication, a U.S.-based Tencent spokesperson emailed CBC News a statement.
"We received the Citizen Lab report and take it seriously. However, with regard to the suggestion that we engage in content surveillance of international users, we can confirm that all content shared among international users of WeChat is private," the spokesperson wrote.
"As a publicly listed global company we hold ourselves to the highest standards, and our policies and procedures comply with all laws and regulations in each country in which we operate. User privacy and data security are core values at Tencent, and we look forward to continuing to sustain user trust and deliver great user experiences."
The researchers at Citizen Lab say they examined WeChat's terms of service and privacy policies for users inside and outside China, and asked for information from Tencent's data international protection office more than once, starting in January. The questions centred on WeChat's policies and how it shares and uses international users' data.
"We didn't get back much that's meaningful and certainly not anything that points towards this type of data practice," said Deibert.
"And furthermore, the company did not reply to us when we sent them questions specifically about our report."
Censoring keywords and images
WeChat is widely reported to have more than one billion users and is the third-most popular messaging app in the world after WhatsApp and Facebook Messenger, according to data from Statista, a German data and analytics company. It's not clear how many people in Canada use the international version of the app, said Deibert.
WeChat is available in the Apple App Store and Google Play Store.
Apple declined to comment on the findings, while Google did not respond to multiple requests for comment.
Citizen Lab previously found that WeChat censors certain keywords sent by users with accounts registered to Chinese phone numbers but not ones with international phone numbers, and that WeChat censored images in China that it deemed to be political.
Last year, Canadian users in group chats with users based in China reported that some of their messages were blocked, according to the National Post.
How it works
Researchers from Citizen Lab set up two group chats using newly created WeChat accounts, one with accounts registered to phone numbers from outside China and another group chat with a user account registered to a phone number from China.
According to Citizen Lab, WeChat scans files and images sent through the app for an MD5 hash, essentially an image's digital fingerprint. The Citizen Lab team gave the same hash to two different images, one that was an image of a political dissident who had died in recent years and another image it determined wasn't sensitive and had not been censored.
"We would send the politically sensitive image entirely amongst international users. And then a minute later, we sent the benign image with the same hash to a China user and that image was then censored," said Jeffrey Knockel, a research assistant for Citizen Lab.
"Unless there is political surveillance being done amongst international users, there's no way to explain how that benign image could've been censored."
They also performed tests using documents and found that sensitive documents were censored for Chinese accounts after being sent between non-Chinese accounts.
Researchers caution they don't know if the same surveillance applies for text messages sent on WeChat.
After reading a copy of the Citizen Lab report, Paul Evans, a professor of Asian international relations at the University of British Columbia, said he will keep using the app occasionally, but he would advise his students, especially those from China, to be careful.
"WeChat, we've been aware for some time that there are censorship and surveillance activities focused on people in China," he said.
"[We] have also been aware that censorship and well, certainly surveillance is possible for those of us outside the country as well."
Deibert said that the federal privacy commissioner should look into his lab's findings.
The British Columbia and Ontario privacy commissioners declined comment and referred CBC News to the federal privacy office. Federal Privacy Commissioner Daniel Therrien also declined to comment.
'Can come back to haunt you'
Former Ontario privacy commissioner Ann Cavoukian said the report signals that privacy commissioners need to take action.
"I would go to great lengths if I was a commissioner to make it clear to everyone here in Ontario, for example, of the consequences of using ... WeChat and that your information may be flowing up to third parties unknown and it can come back to haunt you."
Cavoukian said she wasn't surprised by Citizen Lab's findings and that people in general need to be aware their data is up for grabs.
"I'm not suggesting that other messaging apps don't collect information," she said, citing how Facebook and Instagram collect information to serve users ads. "But the WeChat China context is completely different in terms of the multiplicity of potential uses of your information."
She cautioned that any app based in China is likely to include surveillance of users.
"They are a surveillance-based country and they think it's a great idea and they applaud that. So use that information and interact with them knowingly on the basis of the fact that they engage in tracking and surveillance across the board."