Russian opposition activists have rallied in Moscow, shouting slogans comparing Prime Minister Vladimir Putin to Soviet dictator Josef Stalin. "Putin is Stalin! Putin is Brezhnev! Russia without Putin," chanted the crowd, including former chess master Garry Kasparov, one of the Kremlin's harshest critics who co-heads the democratic, pro-western Solidarity movement. One activist held a big caricature picture of Putin kissing Soviet leader Leonid Brezhnev. Police quickly took it down. Other demonstrators -- from grandmothers to schoolchildren -- unfurled an enormous Russian flag and waved placards demanding fair elections as lines of riot police watched over warily. The opposition says Putin has stifled media freedom and democratic rights when he was president between 2000 and 2008. They also accuse him of blind economic policies similar to the years of stagnation under Brezhnev.