Russian opposition leader Sergei Udaltsov (center) gestures as masked police officers take him for questioning in Moscow on Wednesday, Oct. 17, 2012. In a new sign of a widening crackdown on Russia's opposition, investigators have opened a criminal probe against Mr. Udaltsov and several other activists for allegedly plotting mass riots. (AP Photo/Mikhail Metzel)

Photo by: Mikhail Metzel

Russian opposition leader Sergei Udaltsov (center) gestures as masked police officers take him for questioning in Moscow on Wednesday, Oct. 17, 2012. In a new sign of a widening crackdown on Russia's opposition, investigators have opened a criminal probe against Mr. Udaltsov and several other activists for allegedly plotting mass riots. (AP Photo/Mikhail Metzel)