The goal, as CBS News Correspondent Jim Stewart reports, is to set up warning systems, or trip wires, like one they've established involving crop duster planes, for example.
It works like this: the FBI would be called any time a duster showed up at a small airport unexpectedly or someone wanted to rent one, or be trained to fly one. The Sept. 11 hijackers had checked out such planes as a possible way to spray chemical or biological weapons.
Similarly, officials say they have identified 42 chemical and biological agents, ranging from plague to nerve gas, which will be monitored with trip wires reporting thefts or disappearances from labs. Trip wires have also been set up to report the purchase of any equipment needed to make such weapons.
Another warning system has been set up around the nation's prisons. Numerous calls from inmates in the federal prison system have been traced to known terrorist suspects, officials said. Active recruiting and operational planning for an attack has been detected at a prison in New York state.
Officials are mindful that dirty bomb suspect Jose Padilla was recruited into terrorist ranks while in prison. Other trip wires have been established at several colleges where recruiters with ties to suspected terrorists have been detected. FBI Director Robert Mueller alluded to the search in a recent speech.
"Al Qaeda is still out there working hard to recruit new members and continuing to plot attacks on American targets both here and abroad," Mueller said last week.
"Money transfers" to and from any of dozens of overseas locations will also set off trip wires as will any "unusual apartment rentals" featuring rotating tenets and commercial "post office box rentals."
An obvious question is whether such a series of trip wires would have tipped off authorities to the Sept. 11 hijackers? Certainly some of their activities like flight training and money transfers might have set off alarms. The trick, however, is that someone has to hear them.