Inside China, the videos helped draw in the protesters. A former journalist in Shanghai said he first stumbled upon a vigil on Urumqi Road in the city on Saturday, but went out to join another the next day after seeing WeChat videos of his friends at the rally.

He also shared videos of the protest on WeChat, though he deleted them after 24 hours in an attempt to evade the authorities, who had begun to pursue some protesters. Although his videos were no longer available until shortly after, it changed the minds of two people he thought would be unhappier: his parents.

“My parents, like many Chinese parents, used to think that what I do was meaningless and childish, but in the past two days they have changed dramatically,” said Mr. Zhou. He said his parents now understand why he took part in such gatherings, perhaps in part because they too have suffered under the grip of Covid.

Despite the breakthroughs, some have warned that censors will soon strike, possibly regaining control of public opinion. While he agrees they have been overwhelmed by censors, Han Rongbin, a professor of media and politics at the University of Georgia who studies Chinese censorship, said their work, which has involved pulling down massive numbers of posts and videos, has been very successful. .

The goal of censorship in China is not to keep everyone in the dark, just enough people to ensure that the spread of protest is stopped. “I still think it’s very effective,” he said, “as there are still a large number of people who aren’t sure what’s really going on.”

After the weekend’s massive demonstrations, this week’s gatherings were much smaller, with authorities choking off potential sites with tight security. The question is how effective censorship and other measures will be in deterring further protests in the coming days and weeks.

Video production by Axel Boada And the Mui Xiao.