Ever see John Holschen's of Insights analysis or presentation on Al-Qaeda and terrorist tactics? It's been reprinted and used by OUR military.
You are silly if you underestimate your enemy and you are silly if you disregard risk analysis when deciding on an action.
The 9/11 hijackers were not incompetent and they certainly planned. They took rehearshal flights. They planned how to deal with resistance. While one can conceive of an attack on a mall by clowns, who we American gunslingers can pick off one at a time with a J frame and our superior marksmanship, might a real gun oriented attack by carried out by trained personnel who know how to act as small units and practiced against the random CHL person in ambush?
Of course, not. My point is to be educated and trained. Understand the risks - but it is more fun to posture.