The Tor browser may be best known for anonymous internet surfing, particularly in countries with heavy censorship.

That's no longer true in Venezuela, free speech advocacy group Access Now said Monday.

"It seems that the government of Venezuela has found out how to do a very sophisticated block for the Tor network," Melanio Escobar, Venezuelan technologist and journalist, said in a statement. "The government is moving forward to be as closed as China or Iran."

Venezuela is notorious for internet censorship. In a report published last year by independent watchdog Freedom House, the country scored 63 out of a possible 100 on internet freedom, based on difficulty of internet access, limits placed on content, and "violations of user rights." In comparison, China scored 87 out of 100, Iran ranked 85, and Turkey scored 66.

Despite Venezuela's large oil reserves, the country's collapsed economy has resulted in widespread famine, crime and violent protests. The government has responded by arresting online protesters and torturing them "to reveal their social media passwords," Access Now said. "Under these conditions, anonymity tools like Tor are especially crucial for activists, independent journalists, and civil society actors to stay safe online," the group said.

The Consulate General of Venezuela in New York didn't immediately respond to a request for comment.

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