On the 20th anniversary of Tiananmen they just, two days ago, announced that they were simply shutting down access to Twitter, because there was no way to filter it other than that.
天安門事件20周年の日の ほんの2日前に Twitterへのアクセス遮断を発表しました それ以外にフィルタリングする方法はありませんでした