At 9:15 a.m., Moscow Polling Station No. 104 was packed.
"Something's not right," Anna Grokhovskaya, a young election observer, said as she surveyed more than a hundred jostling students.
She feared it was a "carousel," a falsification tactic that involves groups of people being bused around to different polling stations to vote multiple times.
Within minutes, support was on hand. Ivan Gladkov, who arrived with the roaming mobile group that Grokhovskaya had summoned, said a serious violation was occurring.
The chief election official at the polling station was intoxicated, he added, and the police had been called.
The fuss at Polling Station No. 104 was just one small drama among hundreds unfolding across Russia on Sunday as volunteer observers clashed with elections commission officials during the country's presidential poll.
Organizations recruiting observers sprang up in the weeks and months after widespread allegations of mass fraud during parliamentary elections Dec. 4.
The majority of these volunteers, who worked from 7:30 a.m. until 10 p.m. or later, took part in the mass demonstrations in Moscow during recent months.
"Observers are not very well grounded in the details of the law, but they don't have any illusions about the fact that everything should be fair," Yelena Pakhomova, an election observer at Polling Station No. 54 registered with the A Just Russia party, told The Moscow Times. "When you're under supervision, you behave better."
Pakhomova, 24, who was a member of the elections commission stationed at a polling place for the Dec. 4 elections, said the voting this time was much fairer.
"Everything is very transparent and clean, … and there's an entirely different attitude toward the observers," she said.
Observer organizations made little effort to hide their affiliation with opposition demonstrations and hostility toward Russia's likely next president, Vladimir Putin.
Denis Shragin, 31, an observer representing presidential candidate Mikhail Prokhorov, said he volunteered to be an observer because he was "outraged by the results of the Dec. 4 elections" won by the ruling United Russia party.
Shragin registered at , a volunteer group created by opposition activist Alexei Navalny, and was directed to represent Prokhorov's headquarters. He received training from the liberal opposition Yabloko party.
For the majority of the observers, Sunday's election was their first experience with that kind of work. Almost all said they intended to take part in opposition demonstrations planned for this week.
"You have to do something. You can't just talk and talk," said Kirill Zhilkin, an observer for volunteer organization Citizen Observer at Polling Station No. 218 in Moscow's northwest.
At the same station, observer Yeva Arakcheyeva said she got involved for the same reason she had attended demonstrations Dec. 10 and Dec. 24.
She wanted to feel that she "was not alone and that there were thousands and thousands around me," she said.
At Polling Station No. 2945, observer Alexander Bilyayev was clutching an iPad and counting the people casting their votes.
Also registered through Citizen Observer, he said he would not have got involved if he didn't think the observer movement was a force to be reckoned with.
Citizen Observer said Saturday that it had recruited enough observers to cover all the polling stations in Moscow, St. Petersburg and Yekaterinburg with more than 6,000 volunteers.
Rosvybory said on its website that 17,819 people had registered to be observers. Both Rosvybory and Citizen Observer put out a message on their websites Friday calling for observers to wear a white ribbon, the symbol of the opposition during recent protests.
Some observers said they were inspired out of a sense of shame. Anastasia Dagayeva and Gyuzel Gubeidullina, both 30, said that although their lives are improving, Russia was getting worse.
Dagayeva works for an investment fund, and Gubeidullina is a journalist and founder of the financial news site Finparty.ru.
The number of domestic volunteer observers dwarfed what was sent by international bodies. About 700 foreigners were expected to monitor the election. Moscow officials said more than 11,000 observers were present at 3,380 polling stations in the capital.
Many polling stations visited by Moscow Times reporters had more than one observer. Some had more than 10.
Not all observers drew their inspiration from the events of the past three months, however.
Ilya Ryabikov, 22, a Communist Party observer at a polling station in the Moscow suburb of Balashikha, told The Moscow Times that he had become an observer not because of his political beliefs but because of his desire to earn some money. He refused to say whom he would vote for.
Some observers motivated by a new political consciousness were disappointed when there was little sign of overt falsification.
"I'm really bored here. It's a closed polling station, and there is no ballot-stuffing, no carousels and nothing interesting!" said Daria, 20, by telephone from Polling Station No. 3355 in the southwest of Moscow. "I'm even offended," she said, laughing.
She requested that only her first name be used because her father is a police officer.
The reality differed a lot from what she had read on Twitter, she said, where opposition figures such as environmental campaigner Yevgenia Chirikova, television host Ksenia Sobchak and Navalny kept up a constant stream of information Sunday about dramatic electoral violations.
Many observers across the city said they had not recorded any major violations, though many added that they suspected that serious fraud could occur when ballot papers were counted after 8 p.m.
Daria underwent the recommended training program to become an observer Saturday, one of the last possible opportunities. About 200 participants listened attentively as representatives from Citizen Observer, Rosvybory, long-standing monitoring group Golos and Yabloko advised them on what they would face.
As well as ballot-stuffing and carousels, attendees were warned about the dangers of being slipped laxatives in tea or coffee offered by election officials.
"We are fulfilling a big, historic mission," said Alexei Zakharov, a professor of sociology at Moscow's Higher School of Economics and an organizer at Citizen Observer. "What we are doing will be written about in school textbooks in 20, 30 and 40 years' time."
Behind the observers on the ground in polling stations, each organization provided a support network of mobile groups coordinated from headquarters. Many organizations also offered falsification hotlines.
Citizen Observer's headquarters was next to the Volgogradsky Prospekt metro station. In a room in a call center for banks and other businesses, organizer Yulia Drogova said enough money had been raised via a fundraising campaign on Yandex to rent the premises for four days.
After chasing alleged carousel voters as part of a mobile group, Yevgeny Goifman recalled back at the Citizen Observer headquarters that Prime Minister Vladimir Putin had called the Dec. 10 Bolotnaya Ploshchad protesters "Bandar-logs," referring to the ape-men in "The Jungle Book."
"I don't consider myself a Bandar-log. And so I'm here," he said.
All the mobile groups had a driver, a lawyer and a journalist. Mobile group SAO-2 of Citizen Observer was one of seven teams covering Moscow's Northern Administrative District.
All of its three members said they had voted for Prokhorov, and two sported white ribbons.
Journalist Gennady Gabriyelyan, who was with SAO-2, said he saw the role of the mobile groups as a sort of "election police" who could chase carousels and respond to calls for assistance from observers in difficulty.
He said Citizen Observer was not just a way of forcing free elections but a political tool of the opposition.
"We are fighting for tomorrow," he said.
But the group members were not as inundated with calls as they had expected. During a stop for lunch, lawyer Natalya Yurshina said she was surprised. She had read up on electoral law in preparation, set up a new Twitter account for the day and carried several bags full of legal documents.
"I know it sounds banal," she said. "But I am here for the truth."
Staff writers Natalya Krainova, Alec Luhn and Rachel Nielsen contributed to this report.