As protests continue in cities across China over the government’s harsh “zero-COVID” policy, a separate battle is taking place on social media sites within China and around the world; a fight that is testing the strength of China’s online censorship apparatus, known as the Great Firewall.

Human Rights Watch China Director Sophie Richardson said Chinese officials appear to be resorting to “low-tech approaches” to tamp down online speech even as the protesters have become more adept at getting their messages past government censors.

“Literally police stopping people on the streets, on public transportation, and forcing them to hand over their smartphones so that police can inspect them to see if they’ve got chats about the protests, if they’ve taken pictures or videos, or if they’ve sent these kinds of materials to other people,” she told VOA via Skype on Tuesday.

Some protesters in cities such as Beijing and Shanghai are getting information out about the crackdown by using technology and other techniques to circumvent government censors who are believed to be using an automated system to help block prohibited content.

Over the weekend, researchers noted that outside of China, when people on Twitter tried to share tweets about the protests and the ensuing crackdown at the hands of police, Chinese language accounts intervened to block the information from spreading.

“Numerous Chinese-language accounts, some dormant for months or years, came to life early Sunday and started spamming the service with links to escort services and other adult offerings alongside city names,” according to The Washington Post.

Many Chinese citizens have been able to use virtual private networks – or VPNs – to get over the Great Firewall to post photos, messages, videos and other materials on platforms including Twitter.

Ji Feng, a former student leader of the 1989 Tiananmen Square pro-democracy protests, told VOA that students with VPNs are “jumping over the great firewall,” to gain access to information.

Richardson says those postings have been “an extraordinary breach of the firewall” with Chinese authorities likely to crack down on VPN use.

“As of a few years ago, the use of unauthorized VPNs was criminalized,” she says. “And so we are expecting to hear that people will be prosecuted simply on charges of using that kind of technology.”

The Associated Press reported Tuesday that “videos and posts on Chinese social media about protests were deleted by the ruling party’s vast online censorship apparatus.”

Richardson expects a more complete assessment in the next few weeks of “the extent to which authorities will have used basic garden variety surveillance cameras, which are just legion across all urban Chinese areas now, to identify protesters, and possibly they’ll be used as a basis for prosecuting people who were doing nothing more than exercising their right to free speech.”