Protesters in Moscow Walk Softly, Carry no Sticks Olga Kravets for The New York Times Riot police arrest a protestor in downtown Moscow. MOSCOW - On the empty plaza in a Moscow park, a man unfurled a yoga mat and sat down. Soon enough, two uniformed policemen arrived to confront him. Ringed by a small group of supporters, Vadim Dergachyov, a 29 year old, argued that it is not illegal to sit down in Moscow. But the police - - suspecting that he was protesting the inauguration of Vladimir V. Putin as president - ordered him to stand up. He refused, and the police simply shrugged and walked away. Since Monday, the police have been arresting anyone they think even remotely resembles an anti-government demonstrator, sometimes just because they are wearing white ribbons or even white T-shirts. In response, protestors in Moscow have adopted new tactics, so-called dilemma protests and flash mobs to avoid the mass arrests. The evolving tactics in Moscow are not novel. In his primer on nonviolent protest, Gene Sharp described a dilemma protest as performing an action so inchoate and unorthodox that police are trapped. If they let it happen they are encouraging it, but if they arrest people they risk looking either silly or arbitrary and unjust, which is the point. "This type of activity enables resistance to continue against opponents who are applying extreme repression," Mr. Sharp wrote. Acts of resistance in small groups, he wrote, are effective when larger "bases for resistance have been neutralized, controlled or destroyed by the opponents." In Moscow, protesters following the anti-corruption activist, Aleksei Navalny, have sat in parks, sung in public or simply walked in groups. Several hundred people, many carrying furled yoga mats. Typically, Mr. Navalny posts his location from an iPhone, and invariably hundreds of Muscovites show up to join him. When Mr. Navalny clambered onto the pedestal of a monument in a park as a makeshift podium, the topic was not politics. He roused the crowd with this peculiar rallying cry: "We are just going for a walk!" And the crowd cheered and yelled back, "We are just going for a walk! We are just going for a walk! Since Sunday, the day before the inauguration, when authorities broke up a permitted protest for still unclear reasons, the police have arrested at least 600 activists in Moscow, including the leaders on multiple occasions for several hours. On Wednesday, a court sentenced Mr. Navalny and another protest leader, Sergei Udaltsov, to 15 days in jail for disobeying a police order. "This is a peaceful protest against Putin's inauguration, but it shouldn't look like a protest," Oleg, a computer programmer out at the Kitai Gorod park, about a mile from the Kremlin, said late Monday evening, a mat furled under one arm. That's why we say we're just here to relax, and that's why I brought this mat. On Monday, the authorities answered the new tactics by sending a street sweeping machine with a water nozzle to sprinkle Oleg and others who sat down. It worked, at least temporarily, and there were no arrests. Two days later, amid throngs of tourists eating ice cream and posing for photographs outside the Kremlin gates, a group of mostly young people wearing white ribbons and carrying flowers suddenly broke into song. First it was a perestroika-era protest tune and then a World War II-era army song in honor of the 66th anniversary of the Soviet Union's victory over Nazi Germany. Riot police in black helmets, jackboots and flak jackets moved in almost immediately, joined by a uniformed police officer with a megaphone, who began repeating in a steady monotone: "Dear citizens, your action is illegal. Disperse immediately. The group of singing youths simply walked away. Also on Wednesday, a few hundred young people wearing white ribbons formed a flash mob in an unlikely spot: the middle of a Communist Party march to celebrate Victory Day. Because the Communists had a parade permit, they managed to walk nearly to the Kremlin walls while chanting "Down with Putin!" Mr. Navalny, for his part, has asked Muscovites to simply meander, and has given his idea a name: "The Protest Promenade." Over two days, his followers have meandered through the pleasant, leafy districts of central Moscow, something they might well be doing anyway over the Victory Day holidays - or maybe not. At one point, in a sign of Mr. Navalny's broad support among the affluent, a red convertible Lexus drove slowly beside those walking on the sidewalk. The driver half stood, raised his right hand and offered a crisp salute to the chief of this new ambulatory dissident movement.