Terrorism isn’t about things.
It’s about people. Evil people.
Counter terrorism is not an exercise in stopping things, darn near anything can be used to create mayhem.
It is an exercise in awareness, in knowing who the enemy really is and what he or she really looks like. It is an exercise in seeing, evaluating and reporting precursors to events.
Why else did the the flying imams try to chill citizen reporting of suspicious behavior?
Yes, I always thought the easiest way to destroy in this country would be fire. The US is covered with forest. Many areas have a heavy population surrounded by trees and brush. A couple guys could create a huge firestorm in populated areas with a couple lighters and a car on a dry, windy day.