WeChat targets predominantly political content including images pertaining to government and social resistance.We compare levels of filtering across WeChat’s Moments, group chat, and 1-to-1 chat features and find that each has different images censored we find that Moments and group chat are generally more heavily filtered than 1-to-1.WeChat facilitates realtime filtering by maintaining a hash index populated by MD5 hashes of images sent by users of the chat platform.WeChat implements realtime, automatic censorship of chat images based on text contained in images and on an image’s visual similarity to those on a blacklist.
