China's Internet Firewall Has Blocked Access to Ethereum Block Explorer Etherscan.io

China's Great Firewall, used by the government to regulate access to foreign internet sites, has blocked one of the most popular sources of ethereum blockchain data.

As of Tuesday, etherscan.io, one of the longest-running and most widely used ethereum block explorers, was inaccessible from IP addresses inside mainland China, based on tests performed locally.

According to Greatfire.org, which compiles and monitors a database of sites that are blocked inside China, etherscan.io was still accessible with "No censorship detected" as of Aug. 18, 2019.But Greatfire.org's scanning record shows etherscan.io has become 100 percent blocked since at least Oct. 30, rendering it inaccessible from inside China unless via a virtual private network.

This is likely the first known case of a blockchain explorer becoming an internet firewall target and puts etherscan.io in the company of such blocked information and social media sites as Google, Facebook, Twitter, and Reddit.

It's not immediately clear what exactly led to the blocking of a blockchain explorer in China.

There were reports that cryptocurrency users encoded censored articles regarding the #Metoo movement and a pharmaceutical scandal in China onto ethereum transactions in a bid to bypass internet censorship.

Internet users had been sharing on WeChat the hash of those transactions using etherscan.io, which even prompted WeChat to later block users from viewing the exact etherscan.io URLs from inside the messaging app.

"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."

The new site, which appears identical to etherscan.io, is currently accessible from inside China.

To be clear, a blockchain explorer is merely an online portal that makes it easier for end-users to browse transaction information of a decentralized network.