Kremlin critic Alexei Navalny was fined 300,000 rubles ($5,000) by a Russian court on Thursday for violating canvassing laws ahead of Russia's 2018 presidential elections.
Navalny has organized two big anti-government street protests in recent months and says he wants to run for the Russian presidency in March next year.
Russian President Vladimir Putin has yet to announce his candidacy, but is widely expected to do so, and win.
Navalny said police came to his home on Thursday morning and he was taken to court and charged with violating election canvassing rules by calling for people to participate in unsanctioned rallies via videos on his YouTube channel.
"A fine of three hundred thousand. Later we'll subtract it from the judge's salary," he tweeted after the court decision.
Russia's Central Election Commission has said Navalny is ineligible to participate in the election due to an embezzlement conviction, a charge the anti-corruption campaigner says was politically motivated.
His campaign has come under repeated pressure from authorities and protesters.
Two of Navalny's campaign staff, Leonid Volkov and Nikolai Lyaskin, were also fined 300,000 rubles and 250,000 rubles respectively on Thursday.