In the weeks after a video of a woman shackled by her neck in Jiangsu province went viral in February on Douyin, the Chinese version of TikTok, Beijing censors went to work removing posts that threatened a widespread public backlash against government officials that some charged with not doing enough to curb human trafficking. However, one social media platform with a growing number of Chinese users speaking out against the government remained out of reach for authorities. Mastodon, an open-source microblogging software, was created by German developer Eugen Rochko in 2017 as a decentralised version of Twitter that is difficult...