Thousands of fake Twitter accounts are being used to drown out activists and bloggers protesting the recent presidential elections in Russia.

Widespread reports of ballot stuffing and voting irregularities prompted thousands of Russians to demonstrate in Moscow’s wintry Triumfalnaya Square. Hundreds were subsequently arrested by Russian security forces, including well-known anti-corruption blogger Alexei Navalny.

Protestors began tweeting anti-Kremlin sentiments using the hashtag #триумфальная (Triumfalnaya), which quickly became one of the most-used hashtags on Twitter.

But as Maxim Goncharov, a senior threat researcher at Trend Micro notes, it wasn’t long before #Triumfalnaya messages were drowned out by loud, pro-Kremlin tweets trumpeted by countless Twitter bots.

“If you check this hash tag on twitter you’ll see a flood of 5-7 identical tweets from accounts that have been inactive for month and that only had 10-20 tweets before this day,” said Goncharov.

“To this point those hacked accounts have already posted 10-20 more tweets in just one hour. Whether the attack was supported officially or not is not relevant, but we can now see how social media has become the battlefield of a new war for freedom of speech.”

Meanwhile, security expert Bryan Krebs says he is working with Russian researchers to identify thousands of accounts posting anti-protester or pro-Kremlin sentiments to more than a dozen hashtags and keywords that protesters are using to share news, including #Navalny.

“A review of 2,000 Twitter accounts indicates most of them were created at the beginning of July 2011, and have very few tweets other than those meant to counter the protesters, or to simply fill the hashtag feeds with meaningless garbage,” Krebs confirmed.

“Some of the bot messages include completely unrelated hashtags or keywords, seemingly to pollute the news stream for the protester hashtags… Almost all of the bot accounts are mostly following each other, with a handful of exceptions, as most of the auto-created accounts flooding the protester hashtags are following the Twitter account @master_boot, which looks like it belongs to an actual user.”

Krebs also noted that the Kremlin appeared to be using its official Twitter accounts to criticize those calling the recent elections a fraud, with Russian President Dmitry Medvedev tweeting (and then deleting): “It has become clear that if a person writes the expression ‘party of swindlers and thieves’ in their blog then they are a stupid sheep getting f****d in the mouth.”