"Zero Dark Thirty" is nominated for five Oscars, including Best Picture and Best Screenplay. The film has raised questions about movies based on real events. How close do you stay to the facts? How true do you stay to the facts? And there's the whole subject of torture and the role it did or did not play in finding and killing Osama Bin Laden. The movie's opening is intense, and screenwriter Mark Boal says it's one of the toughest things he's ever had to do.