Just a little-known fun fact? In the early nineteen-eighties an associate of mine co-authored a paper, widely circulated in DC, that asked ( among other things ) "why would terrorists bother building a bomb when there are all those fuel-laden jets sitting on aprons across the country?"
Well now, if that paper was widely circulated; let's hope the pentagon guys have addressed that question. It would be great if DHS has though about it, too. (I hope this is not wishful thinking.)