Amendment I, U.S. Constitution,
"Congress shall make NO law...abridging the freedom of speech."
As I said to the gun control freaks, what part of NO do you not understand?
It is "during time of war" that we citizens have not defended and have abdicated our liberties in the past and subsequently have seen them diminished and trampled upon with impunity.
With that being said, the proper way to handle this "prank" from the presumption of liberty is we do not have to have unconstitutional laws "...abridging the freedom of speech...," for the sake of "security," but we should have civil liability laws enacted and enforced that hold the "cost" of irresponsible speech by citizens accountable.
The pranksters should be financially liable for the disruption their prank caused to the schools and businesses in which they posted the sign and for the cost of the police, FBI, etc., time and effort to track them down to ensure that the posting of the sign was not a true terrorist threat.
The point of my remarks above is to show that we do not have to compromise, give up, or concede that our liberties are not absolute, even "during a time of war."
It would be extremely disappointing to our founding fathers that most of the present day citizens have such a mindset.
"They that can give up essential liberty to obtain a little temporary safety, deserve neither liberty or safety." Benjamin Franklin - 1759
Too late, USA Patriot act I, No.II Coming soon.