Last week, Alexei Navalny, the recently convicted Russian opposition blogger, lawyer and candidate for the post of mayor of Moscow, posted a provocative item on his site. It was an open letter addressed to the present mayor of Moscow, Sergei Sobyanin, accusing him of authorising the theft of pro-Navalny banners from the city's municipal high rises.
"Could you please answer my question?" asked Navalny, 37, tartly. "Why do you, along with your migrant workers for municipal utilities, steal our Navalny banners from the balconies of the residents who have installed them?" As a statement, it was instructive in more than one respect. It illuminated the confrontational style that has characterised Navalny's rapid rise as one of Russia's most visible opponents of Vladimir Putin and his inner circle.
But also, in the reference to "migrants", it suggested why some harbour deep suspicions about Navalny's liberal credentials. Beyond all that is the very fact of Navalny, who was sentenced last month to five years' jail on the trumped-up charge of "stealing" a forest in Kirov region, of being free at all and able to run against Sobyanin.
On that last, puzzling point, theories abound, some conspiratorial and some grubbily pragmatic. The corruption sentence, against which Navalny is appealing, would ban him from holding public office if upheld. His chances of beating Sobyanin, in any case, look remote, according to opinion polls.
One plausible theory is that Navalny was released on bail at the prosecution's request - and for that read, with the Kremlin's approval - because Sobyanin, having called a snap election for one of the most high-profile public offices outside of the presidency, required a credible opposition foil to claim a veneer of legitimacy.
Whatever the real reason, for now at least the charismatic and good-looking lawyer, who has brought together skill with social media, personal flair and a sharply populist critique of Kremlin corruption, has had a prominent platform gifted to him by Putin and his allies. If that is a risky strategy for the Kremlin in the long run, it is because it has opened up a political space that may be difficult to shut down.
Navalny's most striking slogan, charging Putin's United Russia party with being the "party of crooks and thieves", was, he admits, a slip of the tongue - uttered during a radio interview in the run-up to the controversial December 2011 parliamentary election, widely considered to have been marred by electorate fraud. For his part, Putin has assiduously avoided referring to Navalny by name, suggesting that he is, perhaps, aware of the blogger's political potential.
After making his slip, Navalny organised a poll on his blog: "Do you consider United Russia to be the party of crooks and thieves?" Yes, said 97 per cent of 40,000 respondents. It was the 2011 election that first brought Navalny high visibility on the domestic and international stages, as he became a lightning rod for the mass protests that followed, leading to his first two-week-long arrest.
Used to attracting a few hundred to his rallies, the first big one in Moscow after that election drew an estimated 100,000 people. The following year saw Navalny's coronation, as the opposition elected its own leaders. Navalny topped a public online ballot in which 81,000 votes were cast.
That was a peak for the opposition's "white ribboners"; Navalny's mayoral campaign since his release on bail has struggled to attract similar crowds. Photographs on his blog suggest rallies often attended by a few hundred, seeming to confirm claims that the opposition has lost some of its momentum, on the streets at least.
But then Navalny, since emerging as a political activist 13 years ago, has tended to flourish at a remove from the conventions of Russia's opposition politics, excluded, as he has been by an undeclared diktat, from state television. Dismissed by Putin party allies as a "dirty self-publicist" and as a "little hamster from the social networks", he replied publicly in 2011: "Yes, I am a little network hamster! And I'll gnaw through the throats of these cads!" It is precisely his sharp, sarcastic, mocking style that has enamoured Navalny to his many young supporters. While Russia is benefiting from an oil and gas boom, runs his message, it is only a corrupt few who have been enriched by the new wealth.
Although he had been involved in political activism before, through the liberal Yabloko party, it was the launch in 2008 of Navalny's blog detailing corruption in state institutions that brought him to prominence. It also allowed him to launch the fund that has supported his efforts.
The Navalny file
Born: Alexei Anatolievich Navalny on June 4, 1976. He grew up in Obninsk, 100km from Moscow. He studied law at the Peoples' Friendship University of Russia.
Best of times: In February 2011 in a radio interview, Navalny framed a critique of Vladimir Putin's United Russia party that would galvanise opposition, calling them "crooks and thieves", a phrase that has entered the Russian political lexicon.