Leonardo DiCaprio takes on yet another larger-than-life historical figure in Clint Eastwood's new biopic, "J. Edgar." The film follows the career of the FBI's first and most infamous director, J. Edgar Hoover, who held his position and influence through several presidents, from 1935 through his death in 1972. He built the agency into an investigative powerhouse, but burned many bridges along the way, surviving largely through the shrewd collection and use of secret files he kept on every powerful person in the country.