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.