China's Internet censors have cut off the accounts of a number of outspoken rights activists on the hugely popular WeChat messaging app amid a fresh wave of suspensions since the beginning of last month.
Internet giant Tencent Holdings Ltd has suspended more than 300 WeChat accounts and banned around 40 others since new rules on "spreading political news online" come into effect.
"[My messages] have all been deleted, and one of my accounts has been locked," Cheng Kangming, founder of the China Justice and Anti-Corruption Net website, told RFA.
"Most of the accounts being shut down—about 80 percent of them—are those that put out negative news and views [about the government]," he said.
"They will also close your WeChat or [Twitter-like] Weibo accounts if you post sensitive content."
Cheng is no stranger to having his accounts shuttered on popular social media sites, like WeChat, which counted some 438 million monthly active users in June.
"We received a notice from the Ministry of Industry and Information Technology (MIIT) saying that our content was too sensitive," he said.
"I asked them to release the source of their information...[accusing us], but they said they couldn't do that," he said.
He dismissed claims that account closures were linked to clean-ups directed at online pornography.
"This is about negative news and opinions about the government," he said. "They're not going after pornography."
Some of the users frozen or shut down have been told their accounts are being targeted in an anti-pornography campaign, however.
"They are using anti-porn campaigns as a banner under which to control freedom of expression," Sichuan-based activist Pu Fei, of the Tianwang rights website, told RFA.
"We don't accept this, because freedom of speech should be allowed to exist within certain designated boundaries, but there have been no boundaries set down for online pornography," Pu said.
"What's more, Tencent isn't even a law-enforcement agency, so it doesn't have the right to decide which content is in breach of the law," he said.
Twice shut down
He said Tianwang's WeChat account has been shut down twice in recent weeks.
"Some of my friends' [WeChat] accounts have been shut down indefinitely," Pu said. "To my knowledge, they never sent out anything pornographic."
Hunan-based netizen Hu Haibo said he believes the true number of frozen WeChat accounts is far higher than 357, however.
"I know of so many situations like this, and I think that figure is highly dubious," Hu said. "A lot of people have had their WeChat shut down."
"They are starting up again with another attack on online media."
Last month, China imposed new rules on what kind of information can be spread via instant messaging apps, as well as restrictions on accounts broadcasting news content on such platforms.
By Aug. 25, Tencent had suspended 357 accounts and permanently shuttered 46 under the new regulations, official media reported.
Under the new rules, service providers of instant messaging tools like Tencent must enforce the regulations, Xinhua news agency said via its official Weibo account.
In June, Chinese authorities extended a massive censorship operation to target popular social media sites, banning keyword searches linked to the 1989 Tiananmen Square military crackdown 25 years ago and a mass vigil in Hong Kong's Victoria Park.
On the popular Twitter-like service Sina Weibo and similar social media sites, censors quickly located and deleted posts containing the banned terms, while large numbers of accounts and chat groups were shut down, users said.
China's 632 million Internet users, more that 80 percent of whom use smartphones to get online, are frequently faced with a complex system of blocks, filters, and human censorship that is known colloquially as the Great Firewall, or GFW.
Last month, security researchers Trend Micro uncovered a security "backdoor" in a line of routers manufactured in the southern city of Shenzhen, which could allow a hacker to monitor a user's Internet traffic.
The Netcore, or Netis, routers have a password coded into the device's firmware which can open up the backdoor, and all of the routers appear to have the same password, the company found. Independent firmware that could eradicate such a vulnerability is apparently not supported.
While "backdoors" in routers are common, and are often used for technical support purposes, the password to open them up is rarely included with the device, IDG News Service reported on Aug. 26.
Reported by Qiao Long for RFA's Mandarin Service. Translated and written in English by Luisetta Mudie.