so what have you learned? >> reporter: well, anderson, u.s. officials tell cnn that last year the u.s. intelligence used a dossier as part of a justification to get a warrant to secretly monitor carl -- as one of the sources of information that the bureau has used to defend or to support its investigation. this includes approval from the secret court that oversees the foreign intelligence surveillance act known as fisa, to monitor page's communications. the fbi and the justice department would have had to present probable cause that he was acting as an agent of a foreign power, mobile engaging in foreign intelligence gathering for a foreign government. comey and other fbi officials would have had to sign off on