Oliver Stone may have found his Edward Snowden. According to Deadline, even though no formal contract has been signed, Joseph Gordon-Levitt has told the controversial filmmaker that he is interested in playing the infamous former NSA contractor in a new biopic. Stone’s team has already secured the rights to a novel by Snowden—about a whistleblower seeking international asylum—and another journalistic book about his leak of top-secret documents. The movie is set to begin shooting in December …