A rather unsettling thought: Hijacking Clues May Be Red Herrings

The terrorists who attacked the World Trade Center and Pentagon Sept. 11 practiced near-perfect operational planning, coordination and execution before their mission but left behind obvious evidence leading to other operatives who may have supported the hijackings. This begs the question of whether these evidence trails were intentionally left in order to distract U.S. law enforcement from other terrorists.

[ From Signal vs. Noise ]