From News.com:
FBI Director Robert Mueller on Tuesday said secret “national security letters” are invaluable in unearthing telephone and e-mail logs and blamed computer snafus for deceiving Congress about how often the technique is used. . .
. . . The FBI once used 3×5 index cards to track use of the letters but then switched to a more modern database operated by the bureau’s general counsel. But that database has never been linked to the FBI’s home-brewed “Automated Case Support,” a famously archaic system with IBM terminals as a front-end that has been the subject of a series of devastating internal critiques.
What that means is the only way to transfer information from one FBI database to the other is to manually retype it–a technologically backward approach that invites delays and errors.