Welcome to the big leagues, WeChat.

For the past year, the mobile chat app WeChat, or Weixinin Chinese, has been the fresh new face in China’s hyperactive social media, stealing millions of members—not to mention mojo—from its wounded but still potent archrival, the Twitter-like Sina Weibo. WeChat, which boasts 271 million users, functions primarily as a home for private, friends-only chat groups, but it has also come to host more than two million “public accounts,” on which media outlets, business owners, and anyone else wishing to share their views can push out articles to followers once per day. While many WeChat public accounts are affiliated with state-owned media, WeChat has also given rise to “self-media,” or media startups comprising independent journalists and editors who have seized the opportunity to build new brand names and reach a new audience. They have done so free of the high-profile censorship crackdowns that have dogged Sina Weibo and its 280 million members—until now.

On March 13, users visiting some of the highest profile WeChat public accounts— including individuals like legal scholar Xu Xin, self-media like Consensus Net and Elephant Magazine, and the WeChat presence of one of the accounts affiliated with Caixin, one of China’s top finance and political news outlets—found the accounts had been deleted with no apparent forewarning. Visitors attempting to access those accounts receive a message that the given account “has been repeatedly reported,” and upon investigation has been shown to be “in violation of the rules, and all of its functions have been deleted.” The message advises users to stop following the accounts.

Wen Yunchao, an outspoken Chinese blogger and media analyst based in New York, says several dozen WeChat accounts have been deleted. He told Foreign Policy that the accounts span subject matter, including “law, history, and culture.”

The vast majority of those targeted for deletion are politically liberal. The website of Beijing-based Consensus Net features articles on democracy among other topics.Elephant Magazine’scontent, still available on other web platforms, includes irreverent articles like one asking why China’s top leaders like the late Chairman Mao Zedong and former President Jiang Zemin wore their pants so high. For its part, Caixin is known to harbor liberal DNA and push the envelope of what’s considered allowable reporting, although it’s skilled at staying on the safe side of authorities’ invisible red line. (Not every blocked account stood on the same side of the political spectrum: The WeChat presence of the prominent conservative Maoist website Utopia also got the axe.)

Bloggers now banned from WeChat have taken to Weibo to vent their displeasure. Xu asked, “Which of my articles was sensitive? Which law did I violate? And why didn’t I have a chance to answer the charges?” One Beijing-based user who described herself as an e-commerce professional commented that WeChat has “imposed its own law on people who are powerless to resist.” Beijing-based reporter Li Hualiang wrote that self-media, until recently such a promising platform, “is an edifice built on sand.”

In a statement to Hong Kong-based media group iFeng, a spokesperson for Chinese web giant Tencent, the company that owns WeChat, claimed Tencent took the action “to safeguard the user experience.” The statement continued that as a public platform, WeChat “strictly prohibits” what it called “malicious marketing,” as well as pornography, violence, and “political rumors.” In language redolent of government propaganda, the company averred that it “strikes hard” at such content “as soon as it is discovered.” Tencent did not respond to an email request for immediate comment.

Although users have rightly complained the deletions came with “absolutely no forewarning,” recent domestic media coverage contains what, at least in retrospect, look like omens. On Feb. 23, Communist Party mouthpiecePeople’s Daily’swebsite syndicated a story discussing the problem of plagiarism on the WeChat platform. Then on March 10, Sina news portal ran a story bemoaning the proclivity of self-media to spread misinformation, particularly about the Beijing-bound Malaysian airliner that went missing on March 8 with 153 Chinese nationals on board, among others passengers. The article fumed, “apart from still having no information about the flight, what is making families mentally and physically exhausted are the Internet rumors.”

Wen said, “It’s very possible that this is the first action taken by the small working group on Internet security headed by [Chinese President] Xi Jinping.” That group, with a broad portfolio including cybersecurity, Internet culture, and Internet politics, met for the first time on Feb. 27. Wen added that the scale of the crackdown surprised him, making him believe it was done on orders from the Chinese government and was not a prophylactic action driven by the company. The government “waits for a new medium to gain a certain level of influence and then they crack down,” he said.

In fact, WeChat has never shown itself to be a fan of public accounts, despite the function’s popularity. In August 2013, in the name of reducing spam, WeChat collapsed all media accounts into one “subscription folder,” meaning that users had to go to a single access point to view them, and limited the number of push notification from such accounts to once a day. Previously, users who subscribed to many public accounts would see notifications of new articles along side by side with updates from friends within their private circles.

Even before this latest move, WeChat has never been free from censorship. Analysis of messages on WeChat has revealed that the platform is closely monitored by censors. From time to time, specific articles are also blocked on WeChat. One self-media account attache sa warning on all its articles that it may later become unviewable because the information it contains is “too fascinating.” But a wholesale deletion of public accounts is unheard of. Those enticed by WeChat’s latent promise as an outlet for independent media are now wondering whether they had simply enjoyed a false spring.

Bethany Allen, Yiqin Fu, and Alexa Olesen contributed reporting.