Chinese internet giant Tencent has reportedly been surveilling content posted by foreign users on its wildly popular messaging service WeChat in order to help it refine censorship on its platform at home.
WeChat has over 1 billion users globally. It is the most popular messaging app in China and ingrained in daily life, allowing people to do everything from making payments to hailing taxis.
Surveillance and censorship of social media and messaging platforms in China is commonplace. Companies that run such services often remove or block content that is likely to offend Beijing.
But Citizen Lab, a research center that is part of the University of Toronto, said in a report published Thursday, that "documents and images shared among non-China-registered accounts are subject to content surveillance and are used to build up the database WeChat uses to censor China-registered accounts."
Tencent told CNBC it had received the report and takes it "seriously", adding that "user privacy and data security are core values" at the company.
"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. 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," a spokesperson for the company said.
The revelations come as the U.S. becomes increasingly worried about the flow of data from apps and services owned by Chinese companies. Last year, Washington launched a national security review into social media app TikTok's 2017 acquisition of Musica.ly. TikTok is owned by Beijing-based ByteDance.
Citizen Lab made it clear, however, that "there is no evidence attributing Tencent's surveillance behaviours enforced on international WeChat users to the direction of the Chinese government."
The research organization drew their conclusions based on an experiment they ran. They ran two different scenarios — one where they communicated entirely among non-China-registered accounts and a second where they communicated with a China-registered account.
They sent images and documents among the non-China registered accounts to see if they would be picked up by Tencent's censorship algorithm. If they were, then users in China would not be able to see that content.
"Such surveillance was discovered by confirming that politically sensitive content which was sent exclusively between non-China-registered accounts was identified as politically sensitive and subsequently censored when transmitted between China-registered accounts, without having previously been sent to, or between, China-registered accounts," Citizen Lab said.
The researchers made clear that while foreign WeChat accounts were not censored, they were subject to surveillance which then informed Tencent's censorship in China.
The revelations paint a picture of a major technology company in China going beyond its domestic borders to monitor content of its international users.
Previously, there was no evidence that Tencent's censorship machine affected users abroad. But the report now shows that Tencent is surveilling content with its foreign users to help it tighten censorship at home.
— This story has been updated to reflect the comments from Tencent which came after the article was published.