On September 11, one of the first things I recalled was the ending of Clancy's Debt of Honor where a Japanese 747 pilot crashed his plane into the US Capitol during a presidential address to congress. After that, it boggled my mind when Condi Rice claimed that no one could have imagined that the terrorists would crash planes into buildings. Then when the anthrax scare came along, I remembered Clancy's Executive Orders, in which either Iran or Iraq (I don't recall which right now) used terrorists to disperse weaponized Ebola virus at car and boat shows around the US.
And now, as there is talk of widespread smallpox vaccinations (against a disease for which there have been no reported cases in 25 years), I recall the plot of Rainbow Six. In that book, a group of superevil dudes, including some high-placed US government officials, plan the ultimate bio-terror attack. Recognizing the fundamental limitations of bio-weapons (if they are too lethal, victims die before having much chance to spread the disease; if they are not lethal enough, well, then they're not lethal enough), these guys plot a two-stage attack. Introducing the weaponized virus in a way to ensure an initial rapid disbursement (at the closing ceremonies of the Olympics), they are prepared to provide large doses of the vaccine throughout the world to deal with the resulting panic. But they have made the vaccine itself lethal, so many millions more are killed by the vaccine than would have died directly from the virus. (In the book, they intend to wipe out most of the planet's population.) And while a world-wide conspiracy of that order is probably far-fetched (with the possible exception of the Carlyle Group), a bio-terrorist would probably be able to do much more damage by infiltrating a rushed, wholesale vaccination program than through most other possible methods of biological attack. I doubt if there is any more effective method of applying a bio-weapon than direct injection. And don't forget, our president killed hundreds by lethal injection while he was governor of Texas. So I guess I'm saying that I won't be anywhere near the front of the line for smallpox vaccination.