Thanks, MizSterious.
This is probably what I was thinking about, but I forgot the details.
But even if that was only a stupid, but dangerous prank, AQ could have done the same thing -- send legitimate looking samples to wifes of world leaders. If they use it, it's a big success for AQ, if not, they haven't lost anything, it would still terrorize people.
Remember how afraid everyone was about just opening their mail, because of the possibility of anthrax contamination?
It would stop people shopping in stores, buying things via the net or mailorder.
AQ is on record of saying, that they want to destroy the economy of the US.