At a few minutes before 8 in the morning on the eve of Russia Day last month -the holiday that since the demise of the old Soviet Union has marked the birth of the new, free Russia - eight men, some armed, swept silently into an upscale apartment building in the heart of Moscow. When the knock came, Ksenia Sobchak, a 30-year-old native of St Petersburg who many believe is Vladimir Putin's goddaughter (she says she isn't ), answered the door in a negligee. If you read the tabloids, whether in Moscow or London, Sobchak is "the Paris Hilton of Russia, " the country's reigning, and most outrageous, socialite. But if you ask her, after a season of discontent in which tens of thousands of her compatriots have taken to the streets in protest, she is "a political journalist". In the room behind her, her boyfriend, Ilya Yashin, a babyfaced 29-year-old leader of the People's Freedom Party, bolted out of bed.

For six hours the men - a squad from the Investigative Committee of the Russian Federation - tore apart the apartment, neither removing their masks nor dropping their weapons. "You know what's going on, " one of them chided her. "If you had married a good KGB man, it would be another story. " They teased her by reading love letters from an ex-beau aloud in front of Yashin. And they humiliated her by sending a man to shadow her to the bathroom. Millions of Russians had seen Sobchak in various stages of undress before, but for the first time this was not a performance of her own making. In Sobchak's safe, the officers reportedly discovered nearly one million euros and half a million dollars in dozens of envelopes. The state, Sobchak said when she described the episode to me in late June, had made its intentions clear. "Whether it's prison or exile, " she said, "they're out to silence me. "

On that same June morning, several leaders of the opposition in Russia also had their homes raided by investigators. But Sobchak stands apart: in this new time of troubles, as Putin settles back into the Kremlin for his third term as president, few Russians more closely embody the state of the country today - in both its prospects and its hazards - than Sobchak. She has money and, with more than 470, 000 followers on Twitter (making hers one of the most popular private Russian accounts), a following. And she is staking both resources in the fight for, as she puts it, "a better way to live. "

"Please don't call me a revolutionary, " she insisted one night earlier this spring in Moscow as she was waiting to go on the Dozhd (Rain) TV channel. Yet since last fall, when she surprised nearly everyone in Russia and embraced the protest movement, Sobchak has been one of the opposition's loudest cheerleaders, exploiting every available platform - whether on TV, radio, the internet, in print or through Russia's booming social media networks - to call for an end to the country's woes: Putin's reign, the police state, the absence of a free press. She has held court at rallies, looked for electoral fraud at polling stations, flown a hundred Muscovites south to support an embattled regional leader, supplied a protesters' encampment in the capital with latrines and come out in support of a band of female punk rockers who donned masks to storm the biggest cathedral in Moscow. She has been arrested at a protest and endured a brief spell in jail. Still she presses on, risking her lucrative career on behalf of a more democratic Motherland.

The President is showing little mercy, and Sobchak is using every other avenue to defend herself. The state, she says, is playing a game of "class warfare" - trying to incite contempt for her millions. "But in this country, ever since 1917, " she wrote in a recent rebuttal in a Russian newspaper, "one should not play with class hatred - it's giving matches to children. " She continued: "Smear me some other way. I promise, for the sake of peace in my country, to give you plenty of reasons. "