Twitter has announced that it now has the ability to censor content in specific countries, leading critics to fear it may cause increased collusion with governments looking to stop opposition groups — like those behind Russia's recent election fraud protests – from using the site as an organizing tool.

The new capability, announced on Twitter's blog on Thursday, allows the company to censor content on a country-by-country basis, while leaving offending posts visible to users in other countries. Twitter previously was only able to remove content worldwide.

"As we continue to grow internationally, we will enter countries that have different ideas about the contours of freedom of expression," the company wrote on its blog post, sparking speculation that it is preparing to launch in China, where it has been banned since June 2009.

The announcement led to a wave of criticism across the Internet, with many human rights defenders denouncing the move as a devil's bargain with repressive governments that would undermine Twitter's commitment to free speech in an effort to open new markets.

They cited a January 2011 blog post in which Twitter wrote: "We keep the information flowing irrespective of any view we may have about the content." The service was seen as instrumental in facilitating the Arab Spring uprisings that toppled three Middle Eastern governments in 2011.

In Russia, activists with the For Honest Elections movement — who have staged the largest anti-Kremlin protests of the Putin era in response to alleged voting fraud in the Dec. 4 State Duma elections — say they rely on the service as key means for communicating and organizing.

"Twitter is extremely important for us," said Alyona Popova, a spokeswoman for the group. Among other things, activists use the service to gauge public opinion and solicit aid for arrested activists, she said.

A spokeswoman for Twitter said the new technological capability did not reflect a change in the company's policy.

"Our announcement is not at all about Twitter censoring tweets, or any kind of policy or philosophical change in how we feel about the importance of free expression," Rachel Bremer, a Twitter representative, wrote in response to a question from The Moscow Times.

Twitter's removing content "will (and always has) only happen in reaction to valid legal process," she wrote.

Some observers in Russia said they didn't blame Twitter for wanting to expand into markets with more repressive censorship laws — something Google and other Internet companies have already done — and that Russian Internet users, even opposition-minded ones, had nothing to fear.

"I don't think it will influence anything," said Ilya Varlamov, a prominent blogger and a co-founder of the League of Voters, a newly formed grassroots group promoting free and fair elections. "Twitter is too fast. By the time the government would get around to blocking content, it would already be too old to matter."

Anton Nosik, a journalist and electronic media entrepreneur, also said there was no reason to panic. "As long as Twitter doesn't have an office in Russia, it's not subject to Russian law."

But others were less optimistic.

"I really regret Twitter's mercantile decision to bow to local dictators," wrote journalist Oleg Kozyrev on his LiveJournal blog.

In an exchange of Twitter messages with The Moscow Times, Kozyrev wrote that Twitter's decision could have negative consequences for the opposition.

"It's easy to censor bloggers and, more importantly, hashtags," he wrote, referring to a feature that allows like-minded users to quickly find each other.

Popova, of For Honest Elections, said she too was worried about the new rule, but she didn't expect a crackdown on Twitter or the Russian Internet anytime soon.

"What we're doing is completely legal. Plus, it's in no one's interest to crack down. The public backlash would be too strong," she said.