WeChat surveils international accounts to decide what to censor for Chinese users, study says

Research group Citizen Lab finds WeChat screens overseas users for sensitive content, which it then bars from being received by Chinese accounts. Findings are likely to add fuel to concerns in Washington about data security when Chinese tech firms are involved. — SCMP

WeChat, the Chinese messaging app, is systematically monitoring the content sent by international users to build up its censorship algorithms applied against accounts registered in China, a new study has found.

Researchers at Citizen Lab, an academic research lab at the University of Toronto, determined that WeChat screens images and documents shared by accounts registered outside China after they are sent, then adds the digital signature – or “hash” – of any files deemed sensitive to a blacklist. Those files then cannot be sent or received by China-registered users.