i'm not sure it's accurate to infer from that a government plot to execute the citizens. although....with this government, who knows

i can tell you what i have been involved in, and it's not classified. it is preparation for that large attack that requires a suspension of civil liberties for a large portion of the population.
we know this is a possibility. i am surprised it has not already happened.
as a nation of free people, we have an immediate negative reaction to the idea that our government might suspend our rights and restrict our activities. we should know that under the right circumstances, they will.
one of the reasons the SARs virus didn't spread more, is that the governments of the countries in which the virus spread first, and fastest, were able to contain the movements of the people. villages were quarantined, markets shut, people confined to homes. there was no question that these governments had the right to do these things and the people did not object.
if the same thing were to happen here, we would not be so compliant.
we have prepared for many years to confront the super bug, or whatever. now we add the terrorist threat of dirty bombs, introduced diseases, etc. it's not new....but it is a little scary when you have an admin that has shown a disregard for the law already, and might not think twice about using excessive force to do as it wishes.