Like many subjects, there's been an astonishing amount of ignorance displayed. But I suspect the FBI, and certainly the airlines, would rather err on the side of caution while the public eye is upon them. Simply to avoid the same astonishing amount of ignorance to combine with social (and professional) media causing a panic about air travel.
I certainly don't know enough about the actual systems and interfaces to know whether it's impossible, plausible or likely. But I KNOW what I know, and by inversion, what I don't know. I use this knowledge to try my best to not display my astonishing amount of ignorance of say, animal husbandry.
John