Artyom Kolpakov used to shrug when he came across occasional appeals on social media sites to protest against Russian Prime Minister Vladimir Putin and his government.

I didn't see the point really, he said.

But something changed when, clicking through amateur videos and online testimonies documenting cases of ballot-stuffing and repeat voting, he saw others shared his outrage at Putin's party's victory in Sunday's parliamentary election.

On Monday evening, Kolpakov, 38, was among several thousand Russians who took to the streets of Moscow in the biggest opposition protest in years.

Such protests against Putin's rule, as president from 2000 to 2008 and as prime minister since then, have rarely drawn more than about 200 people, some of them Soviet-era dissidents and others activists in marginalized opposition groups.

Typically, they are quickly dispersed by heavy-handed riot police. But Sunday's rally attracted about 5,000 people and a similar rally on Tuesday drew several hundred.

Many were responding to calls on social networking sites VKontakte and Facebook to continue the revolution, and tweets sent by protesters from Triumfalny Square in central Moscow.

For the first time really the online presence has transformed offline politics, said Konstantin von Eggert, a commentator for Kommersant FM radio. The whole thing works like a snowball. This is definitely the start of something that will stay in Russian political life.

CROSSING A LINE

Just as news of planned rallies spread on social media, protesters and opposition forces used Twitter to keep each other up to date on the whereabouts of detained leaders.

The wife of Alexei Navalny, a blogger now serving a 15-day jail sentence for his role in Monday's protests, took up his twitter feed on Tuesday. Later in the day, a follow-up protest at which police detained about 300 people was streamed live on the Internet.

By Wednesday afternoon, more than 13,000 people on Facebook and 6,000 on Russia's Cyrillic-language VKontakte had pledged to attend a fresh protest near the Kremlin on Saturday. Another 11,000 people said they maybe would join.

The links for the protest can be found at facebook.com/events/198328520252594/ and vkontakte.ru/event32872901.

It's absolutely a Facebook story. It's not as if there is some kind of organizer of this, some kind of villain, veteran journalist Sergei Parkhomenko told Dozhd TV, an independent cable and Internet television station that has been one of the only broadcasters to cover the opposition protests.

For Kolpakov, who lives on the outskirts of Moscow and works at a recording studio specializing in children's songs, new media has been instrumental in changing his view of Putin since he won popularity by restoring order following Russia's difficult transition to a market economy in the 1990s.

During Putin's first term, I was happy that he restored some kind of order. Then it became clear this order was not for the good of the country but for the good of his inner circle, he said.

It takes time to understand that the authorities have crossed some kind of line.

OUTRAGE AFTER ELECTION

Sunday's election was, for him, the moment that line was crossed. Kolpakov drove an hour to the centre of Moscow to take part in Monday's protest, ignoring his wife's pleas to stay safely at home with their one-year-old daughter.

He had already volunteered as an election monitor after reading online allegations that Putin's United Russia party was trying to bribe and bully voters in the run-up to the election.

Kolpakov saw no foul play at his polling station in Shchyolkovo, east of Moscow centre, where he says the Communist Party won almost twice as many votes as the ruling party.

So he was stunned when he heard the official result registered United Russia leading the pack with 46.6 percent of the vote in Moscow.

His outrage grew when he saw some of an avalanche of video clips online, most of them apparently shot by disgruntled citizens and election observers using smart phones.

One clip, which has had more than 1 million clicks, gives a bird's eye view of an election official in Moscow calmly ticking off a stack of ballots, apparently preparing to stuff the urns with votes for United Russia.

In another, Kolpakov says a group of so-called merry-go-round voters are shown being bused from one polling station to another.

Yet another testimony widely shared on networking sites shows the disparity between scans of hand-counted voting results

and those posted on the Central Election Commission's website.

A DIFFERENT PICTURE ON STATE TELEVISION

The picture painted by state television, which is dominated by positive coverage of Putin and President Dmitry Medvedev, is very different.

It has been silent on the protests, reporting marches by pro-Kremlin youth groups that were organized to drown out anti-government demonstrators meeting at the same square in central Moscow on Tuesday.

How do you feel when you understand that you are being lied to, that people take you for an idiot, that they are wiping their feet on you? Kolpakov said.

People are angry and it's natural. The temperature is rising. Our authorities must understand that if this is repeated, more and more people will take to the street.

Medvedev, presents himself as the iPad-toting, Internet-savvy modern face of Russia, dismissed such videos as inconclusive evidence and thanked citizens for backing United Russia.

In an embarrassing incident, an obscene post by a United Russia deputy calling anti-government bloggers stupid sheep among other things was retweeted on Medvedev's Twitter feed after midnight on Tuesday.

The tweet was quickly deleted and the Kremlin subsequently blamed a technical support worker who unacceptably interfered with the feed @MedvedevRussia.

THREAT TO KREMLIN?

The ability of social networking sites to mobilize a large group of Russians is a new and powerful tool that could give the Kremlin cause for concern as Putin plans a return to the presidency in a March election.

A Twitter revolution is when people stop messing around on twitter, and start coordinating action through it, tweeted Ilya Varlamov, whose twitter followers grew by several thousand to almost 6,000 throughout the day on Tuesday.

Muscovites have taken the expression 'Twitter revolution' literally, he said, commenting on live cell phone streaming of people gathering outside a court house where activists were on trial after overnight arrests.

Many observers are still skeptical that an Arab Spring is about to sweep Russia.

Although more than one third of Russia's population now have access to the web - or 50.8 million people, says Internet marketing research group ComScore - only a small percentage are politicized and they are mainly in Moscow and other big cities.

Often there is no alternative to tightly controlled media in the Russian provinces, where the authorities hold the most sway with voters.

Let's be honest, so far the Internet and social media have influence only in big towns and cities, said Gennady Gudkov, an opposition lawmaker with the left-leaning Just Russia party. It doesn't have much sway in the regions and provinces.

FEARS OF CRACKDOWN

Many bloggers fear the Kremlin will act to reign in Russia's vibrant blogosphere, if it becomes too influential. Some bloggers have already been prosecuted offline under libel law and Russia's wide-reaching law on extremism.

Distributed denial of service (DDoS) attacks - attempts to make a computer or network unavailable - have in the last few days shut down a large number of media websites. Russia's most popular blogging site, LiveJournal, was hobbled.

The cyber attack also simultaneously crippled the websites of leading radio station Ekho Moskvy - owned by state energy monopoly Gazprom - Kommersant newspaper and other top media outlets. Russia's main independent vote monitor, Golos, was another targeted.

I am sure the authorities will very soon try to introduce legislation that will restrict the Internet, Von Eggert said, although the Kremlin has denied such suggestions.

The cyber attacks spurred bloggers and Twitter users to step into the gulf, with Navalny and others offering up their blogs as a clearinghouse for evidence of election violations.

Popular writer Boris Akunin polled readers of his blog on whether they believed the elections were rigged: Only 243 out of 8,129 respondents thought the vote was fair.

I will address a few words to Vladimir Vladimirovich (Putin): 'I am sorry for you,' he wrote at Borisakunin.livejournal.com. 'You don't have to be Nostradamus to predict your future.'

WILL ONLINE LEADER BECOME OFFLINE LEADER?

New media, and the protests they have helped spawn, may also be in the process of building Navalny, 35, into a much more potent opposition force.

Until now he has been an informal leader of the disenchanted, campaigning online against corruption, as well as showing nationalist tendencies. But his jail sentence on Tuesday could turn him into a symbol and leader of the protests.

In a tiny courtroom where he was sentenced to 15 days in jail for obstruction of justice during Monday's protest, Navalny said the Kremlin would seek to silence anyone who spread the word about what he said was obvious vote-rigging.

The elections were falsified, Navalny, looking exhausted and angry, told Reuters in the stuffy court opposite the old headquarters of the KGB secret police on Lubyanka square.

The very acknowledgement of this fact will be deadly for the regime, and they will do their utmost to shut the mouths of everyone who talks about it openly, said Navalny, looking gaunt and without laces in his dirty boots.

Using his blog to illustrate the absurdities of Russia's corrupt bureaucracy, Navalny shot to prominence by challenging state companies such as pipeline operator Transneft to explain millions of dollars of unorthodox payments.

He has also challenged Putin directly, accusing him of ruling a corrupt elite as chairman of the board of Russia Inc. and branded his party swindlers and thieves, a phrase that haunted the party during its election campaign.

Ekho Moskvy editor Alexei Venediktov wrote on his station's website that the arrest could turn Navalny into a much bigger problem for the Kremlin.

Navalny's arrest was a political mistake. Jailing Navalny is the transformation of an online leader into an offline one, he wrote.

(Additional reporting by Alexei Anishchuk, Maria Tsvetkova and Guy Faulconbridge; Editing by Timothy Heritage and Peter Graff)

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