To comply with Chinese law, Tencent’s WeChat must censor content in the app for users in the country. However, the censorship in WeChat appears to extend beyond the country’s borders. A study from the University of Toronto’s Citizen Lab shows that users who initially register in China continue to face censorship when switching to an international number.

It was believed the censorship only applied to content being sent to a mainland China phone number.

This extra-territorial application of information controls is quite unique, and certainly a disturbing precedent to set,
– Ronald Deibert, director, Citizen Lab

WeChat’s censorship involves removing certain keywords and URLs from messages.

The study also found WeChat has stopped warning users when it blocks message content. It now removes banned words without a special warning.

By removing notice of censorship, WeChat sinks deeper into a dark hole of unaccountability to its users,
– Deibert