But as the latest bomb plot in Yemen shows, little stays hidden for long these days.
In the post-Sept. 11 world, even the most sensitive intelligence operations quickly become daily fodder as the 24-hour news cycle, the Internet and media-friendly politicians give the story momentum. And it's often senior government officials and the intelligence community who spread the juiciest details.
Twice a week, local seniors in Warrenton, Virginia, flock to a hip new dinner spot called the Bistro on the Hill for good food, a great view, and musical accompaniment by a retired piano player from a nearby Nordstrom's.
Many headlines and stories (including some of ours) have been saying that a "double agent" infiltrated al-Qaida in the Arabian Peninsula and foiled a plot to get another underwear bomb aboard a U.S.-bound passenger jet.
But we've been looking at definitions of spy terms and think that based on what we have been told so far, the person at the center of the story wasn't a double agent.