Riot police guard as demonstrators attend a massive protest against Prime Minister Vladimir Putin’s rule in St.Petersburg, Russia, Saturday, Feb. 4, 2012. Several thousands of Russians march downtown St.Petersburg on Saturday to demand an end to 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). (AP Photo/Dmitry Lovetsky)