An open letter from a Chinese student activist that had been censored after going viral on social media in China has been published in a harder-to-erase spot: the ethereum blockchain.

“Now her message is engraved into the Ethereum blockchain and will live as long as Ethereum itself,” wrote Leo Zhang, research lead at Iterative Capital Management, in a blog post.

The letter, published in English and Chinese, alleges that author Yue Xin was forced to destroy a request for information about a decades-old sexual misconduct case at prestigious Peking University, where she was a student. The case, involving a student who allegedly killed herself in 1998 after harassment by a professor, has become a rallying cry for China’s #MeToo movement, Quartz reports. In the letter, Yue says she hasn’t been able to return to school since authorities came to her dorm room in the middle of the night and effectively sent her home to her parents.

It’s unclear who posted the letter to the blockchain. The document has also been shared by media organizations outside China and shared on GitHub. Some social media users apparently dodged censors in China by posting rotated images of the letter and other materials related to the case.

On Weibo and WeChat: shifting photos upside down/rotating around to resist censorship over Peking U and Yue Xin. pic.twitter.com/NGVhwZGlb9 — ElephantRoom (@elephantroomCN) April 24, 2018

The post will likely be impossible to scrub from the ethereum blockchain, since later transactions in the chain depend on previous records in that shared ledger, a standard feature of cryptocurrencies. But it will also be difficult for anyone not pointed to it to spot, since even regular cryptocurrency users don’t routinely scan the underlying blockchains for such messages. The Chinese government could censor social media messages that point to that spot in the chain or even disrupt access to websites that make it easy to explore blockchain records, meaning the blockchain post may ultimately be mostly symbolic.