U.S. counterterrorism operatives are helping Russian security agents in the hunt for four female potential terrorists, including a "white widow" -- the wife of a dead terrorist -- who could already be inside the massive security zone set up for next month's winter Olympics. Ruzanna Ibragimova, the 22-year-old widow of a jihadist killed by Russian security forces, is believed to have traveled from Dagestan to Sochi, according to a Russian security bulletin obtained by FoxNews.com, along with photos of her. The bulletin and photos were distributed by the Russian security force FSB and Sochi security officials to U.S. and other...