May 19, 2022

Report: “We Chat, They Watch: How International Users Unwittingly Build up WeChat’s Chinese Censorship Apparatus”

From the The Citizen Lab, University of Toronto:

Key Findings

  • We present results from technical experiments which reveal that WeChat communications conducted entirely among non-China-registered accounts are subject to pervasive content surveillance that was previously thought to be exclusively reserved for China-registered accounts.
  • Documents and images transmitted entirely among non-China-registered accounts undergo content surveillance wherein these files are analyzed for content that is politically sensitive in China.
  • Upon analysis, files deemed politically sensitive are used to invisibly train and build up WeChat’s Chinese political censorship system.
  • From public information, it is unclear how Tencent uses non-Chinese-registered users’ data to enable content blocking or which policy rationale permits the sharing of data used for blocking between international and China regions of WeChat.
  • Tencent’s responses to data access requests failed to clarify how data from international users is used to enable political censorship of the platform in China.

From the Introduction

WeChat is the most popular social media platform in China and third in the world.


In previous work, there was no evidence that these censorship features affected users with accounts that are not registered to China-based phone numbers. These users could send and receive messages that users with China-registered accounts could not. In this report, we show 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.

By engaging in analysis of WeChat privacy agreements and policy documents, we find that the company provides no clear reference or explanation of the content surveillance features and therefore absent performing their own technical experiments, users cannot determine if, and why, content surveillance was being applied. Consequently, non-China-based users who send sensitive content over WeChat may be unwittingly contributing to political censorship in China.

Direct to Full Text Report

Direct to Full Text Report (60 pages; PDF)

See Also: Summary Report, Infographics: “We Chat Explained”

About Gary Price

Gary Price ( is a librarian, writer, consultant, and frequent conference speaker based in the Washington D.C. metro area. Before launching INFOdocket, Price and Shirl Kennedy were the founders and senior editors at ResourceShelf and DocuTicker for 10 years. From 2006-2009 he was Director of Online Information Services at, and is currently a contributing editor at Search Engine Land.