In the hallway, we constantly see a poster with names and pictures of spies that have been caught, as well as short narratives of what their crimes were and how much time they're serving. These posters really exist in secure government facilities, and prominently displayed on all of them, since the events of this movie took place, is a photo of Robert Hanssen.
The film's translation in Russia is "Treason"
The German translation of the title is "Unmasked", the German alternate title means "Unmasked - Treason on the top level".
After the opening scene, code quickly flashes and is reduced to the movie title. The scrolling code is a Linux procedure that mounts (connects to) networked data sources such as Unix, Windows and Novell file systems.
During an appearance on the radio program "Fresh Air with Terry Gross," the real Eric O'Neil told Gross that the real Robert Hanssen had a crush on the movie star Catherine Zeta-Jones, and he used to watch her movies at the office while he was supposed to be working. This is briefly referred to in Breach (2007) when investigators find DVDs of The Mask of Zorro (1998) and Entrapment (1999) among Hanssen's effects.
Hanssen tells O'Neill, "if I ever catch you in my office again, you're gonna be pissin' purple for a week." The real Robert Hanssen's undoing was a George S. Patton quote about "the purple-pissin' Japanese", a quote which Hanssen was fond of repeating. The FBI had paid a Russian agent $7 million for the KGB's file on the American mole - known to the KGB at the time only as Ramon Garcia. The file included a note of the mole about "purple-pissing Japanese" and Robert Hanssen became the prime suspect in the investigation. The FBI arrested Hanssen three months after receiving the file. The film concerns the last two months of the investigation.
In the movie, Robert Hanssen (Chris Cooper) is obsessed with Catherine Zeta-Jones. In reality, Cooper and Zeta-Jones won their respective Best Supporting Actor/Best Supporting Actress Oscars at the same Academy Awards ceremony in 2003.
In the film, Hanssen has surreptitiously videotaped himself having sex with his wife and instructed O'Neill to mail the tape to his friend James Hofsteller in Germany. Actually, Hanssen set up a closed-circuit camera and monitor (using equipment belonging to the FBI) so his friend, whose name is actually Jack Hoschouer, could watch during his visits to the Hanssens.