One of the FBI's 10 most wanted fugitives, Semion Mogilevich cuts a frightening figure. Called the "Brainy Don" (he has an economics degree), the Ukrainian-born mobster's gang has a multinational reach, with his hands allegedly in everything from a Pennsylvania-based company that defrauded investors of $150 million to the East European gas trade. His other reputed crimes include murders, arms dealing and drug trafficking. Mogilevich was arrested in Moscow in 2008 for tax evasion, but, brainy and crafty as he is, was released the following year.