China’s Great Firewall, a tool used by the Chinese government to block some websites within the country, has blocked the most popular Ethereum blockchain explorer Etherscan.

According to data from the non-profit organization Greatfire, which monitors a database of websites backed from IP addresses in China, the Ethereum blockchain explorer wasn’t blocked as of August 18 of this year, but is now “100% blocked.” This means that form within China, it’s only possible to access it using a virtual private network (VPN).

The block was first spotted by CoinDesk, which noted this is the first known case of a blockchain explorer being blocked by an internet firewall. Websites blocked in China include Reddit, Twitter, Google, and Facebook.

It’s believed the website was blocked because some within China were using the Ethereum blockchain to share content that is censored by China’s firewall. By encoding censored articles regarding a pharmaceutical scandal in China and the #MeToo movement on ETH transactions and then sharing these transactions using Etherscan, users managed to bypass censorship.

Matthew Graham CEO of blockchain investment firm Sino Global Capital, was quoted as saying:

Some have used this feature to post sensitive messages without the need to worry about the message being blocked or removed, or their identity being exposed. Anyone with a blockchain explorer like Etherscan can view these messages, so it is not surprising that this website has come in the crosshairs of internet censors

Etherscan’s founder and CEO Matthew Tan revealed the firm did notice the ban “within the last 3 months,” but didn’t know what prompted the ban. Some are now using a substitute website, cn.etherscan.com, to bypass the ban. Other Ethereum blockchain explorers are notably accessible from within mainland China.

Featured image by Macau Photo Agency on Unsplash.