"The capacity of fiber optics is so much greater than other communications media
    or technologies, and it's also immune to the stick-up-an-antenna type of
    eavesdropping," said Jeffrey Richelson, an expert on intelligence technologies.

    To listen to fiber-optic transmissions, intelligence operatives must physically
    place a tap somewhere along the route. If the stations that receive and transmit
    the communications along the lines are on foreign soil or otherwise inaccessible,
    tapping the line is the only way to eavesdrop on it.

    The intelligence experts admit there is much that is open to speculation, such
    as how the information
    recorded at a fiber-optic tap would get to analysts at the National Security
    Agency for review.