Despite these concerns, there is limited technical research into the operation and scale of content monitoring and filtering.
In this report, we provide the first systematic analysis of keyword censorship and URL filtering on We Chat to determine how the app filters content and the type of content that is blocked.
We found a greater number of keywords blocked on group chat compared to one-to-one chat, which suggests that communications on group chat are specifically targeted, potentially because group chats can reach a larger number of users.
In both chat modes, users are no longer presented with a warning message when they enter blocked keywords, as indicated by previous reports.
Operating a chat application in China requires following laws and regulations on content control and monitoring.
Accordingly, the popularity of We Chat has also been met with suspicions of surveillance and media reports of censorship.
Documenting censorship on a system with a server-side implementation such as We Chat’s requires devising a sample of keywords to test, running those keywords through the app, and recording the results.
We used a sample of keywords found blocked on other apps used in China and systematically tested that sample in two modes: one-to-one chat and group chat.
Failure to comply can lead to fines or revocation of operating licenses.
The five suspects were nabbed less than 24 hours after the report was filed. It is not known why the report was made more than a month after the incident. Chandra said the girl claimed that when she met the boys, they invited her to go for a walk to an abandoned house and she followed them.
"Later, she told them that she did not want to continue but the boys allegedly forced her to follow, saying that they only wanted to talk and would take her home after that," said Assistant Commissioner (AC) Chandra.
We found that keyword filtering is enabled on We Chat for users with accounts registered to mainland China phone numbers.
Filtering remains enabled even if users later link their account with a non-mainland China number, which means that users with accounts registered to mainland China will remain under censorship regardless if they travel or unlink their Chinese phone number from the account.