CAPTION ADDITION ADDS NAMES OF DEMONSTRATORS – Russian popular writer Dmitry Bykov, flanked by opposition leader Alexei Navalny, third right, and environmental activist Yevgenia Chirikova, second right, holds an anti-Putin poster during a massive protest against Prime Minister Vladimir Putin’s rule in Moscow, Saturday, Feb. 4, 2012. Tens of thousands of Russians flooded downtown Moscow on Saturday to demand an end to Prime Minister Vladimir Putin’s rule, casting a strong challenge to his bid to reclaim the presidency in March. Saturday’s crowd appeared to be even bigger than two similar rallies held in December, despite temperatures plunging to minus 20 C (minus 4 F). The poster reads “Don’t rock the boat, our rat is about to barf.” (AP Photo/Sergey Ponomarev)
