GreatFire suggests the precipitous traffic decline about eight hours ago was because of the government moving "one step closer to fully separating the Chinanet from the Internet."
Google has experienced a precipitous drop in traffic from China, which a Web-monitoring group attributed to the search engine being "blocked" by the government.
Data provided by Google's Transparency Report shows a sharp drop off in traffic -- to roughly half the normal amount -- to Google's Web sites as of early this morning California time.
GreatFire.org, which performs real-time monitoring, suggested that the drop meant the Chinese government is "one step closer to fully separating the Chinanet from the Internet."
It wasn't immediately clear whether the block was intended to be long-lasting, or whether it's been lifted and Chinese Internet users will be able to connect to Google when they wake up. It's 3:50 a.m. in Beijing right now.
Google has been wrestling with censorship in China for more than half a decade. In April, Google Drive was blocked. Even after switching to a Hong Kong domain in 2010, sensitive topics remained off-limits.
Google sent CNET a statement today saying: "We've checked and there's nothing wrong on our end."