Whiteboards line the walls of this lab deep inside the Defense Intelligence Agency's Washington headquarters, covered from floor to ceiling with hand-scrawled computer code and technical notes. One item stands out at the center of the room's rear wall:
"Attention should also be given to opinion, comments, and jokes of common people."
This axiom, from the original al-Qaida training manual, was a reminder from the terror network's leadership to its foot soldiers that even the most benign communications can provide invaluable lessons about an enemy. It is posted next to another quotation, this one from DIA Director Vincent Stewart, that says 90 percent of intelligence is publicly available.