While cryptocurrencies have been torched in China, their fellow blockchain technology, NFTs, have stayed relatively unscathed. There currently exists no regulation of the digital collectibles in the country, and people can buy them freely from online marketplaces—although they must pay in renminbi, not BTC or ETH, and the tokens are also not built on popular blockchains like Ethereum, but rather ledgers under Chinese regulators’ purview.

Even so, their fortunes may now be turning as China looks to tighten its grip. This week, Tencent, the domestic tech giant behind the country’s ubiquitous social app WeChat, froze several accounts on the app that were linked to NFTs. According to a statement from the company, this was to “rectify” public accounts in order to “combat speculation in virtual currency transactions.”

An official account from WeChat, on China’s social website Weibo, posted Wednesday that Tencent-verified accounts on its platform can display NFTs, but cannot facilitate secondary-market sales (which are restricted by China’s Cyberspace Administration). Similarly, so-called mini programs on WeChat can support NFTs sales exclusively as “gifts within the primary market,” and only in collaboration with blockchains registered with the cyberspace agency.