Russian opposition leader Sergei Udaltsov, left, is escorted by police officers for questioning in Moscow, Wednesday, Oct. 17, 2012. In a new sign of a widening crackdown on Russia's op

 

              Russian opposition leader Sergei Udaltsov, left, is escorted by police officers for questioning in Moscow, Wednesday, Oct. 17, 2012. In a new sign of a widening crackdown on Russia
Russian opposition leader Sergei Udaltsov, left, is escorted by police officers for questioning in Moscow, Wednesday, Oct. 17, 2012. In a new sign of a widening crackdown on Russia's opposition, investigators on Wednesday opened a criminal probe against leftist leader Sergei Udaltsov and several other activists for allegedly plotting mass riots. (AP Photo/Mikhail Metzel)