Are you sure they were compliant? At the time, BBC wrote https://www.bbc.com/news/world-asia-china-28156725 https://www.bbc.com/news/world-asia-china-28156725

Are you sure they were compliant? At the time, BBC wrote https://www.bbc.com/news/world-asia-china-28156725 https://www.bbc.com/news/world-asia-china-28156725 that "In May, some Line users in China complained that the app had started to censor sensitive terms related to the 4 June anniversary of the Tiananmen Square massacre" but "A Line spokesman told Bloomberg that its users in China had not been able to access all services since 1 July, which was the anniversary of Hong Kong's handover to the mainland. Tens of thousands took to the streets of Hong Kong that day in a major pro-democracy protest. A representative of anti-censorship site GreatFire.org told Reuters news agency this was not a technical malfunction, suggesting the services were blocked because they allowed users to share photos." Censoring well-known keywords is necessary, but not sufficient to run a social media service in China. You also need a large team of human censors looking for signs of new protests and suppress them as fresh pictures keep getting posted.