[Catspaw]

If they're not going for a specific target, but an area, a commercially available GPS would probably work (say the middle of DC, NYC or LA). But if they want to hit a specific target like the 9/11 hijackers, they'd need a military unit or do it before the signals are degraded. But it seems like a lot of trouble when all it would take would be someone riding a subway in NYC.

[Iris7]

Sorry, Cat, but "simple" anthrax dispersal methods like throwing the stuff around in a subway, explosive dispersal of packets, etc. have a kill likelyhood in the dozens or hundreds per packet. A full fledged aerial dispersion of anthrax of the quality used in the letters in 2001 could be expected to kill one to three million people with only hundreds of pounds of agent if the weather was "right" and the "crop dusting" accurately placed (within a few hundred yards.)