More like "tens will die."
Seriously, there's limits on how much payload an R/C plane can carry. 100 planes equals 100 operators flying them, and the tangos will start having OPSEC issues. Also, R/C planes ain't the easiest things to fly.
There are some of these chemical weapons, which stick to surfaces, and less than a milligram is lethal.
IN THEORY, less than a milligram is lethal.
The problem is distributing a small quantity of agent so that lots of people come in contact with a milligram.
It's not easy to solve.
And of course there are the biological weapons, like smallpox, where it may not be discovered until days later, by which time many more people are infected. The "Dark Winter" sallpox attack simulation started with just a few infected cases in I think just one city, and when they stopped it, worst case, there were over a million dead.
The "Dark Winter" worst-case scenario specifically excluded standard prophylactic techniques and assumed that the average American was dumb as a box of rocks.
They were spraying the stuff from rooftops, and the cops came and asked them to stop because people complained about the smell.
Then they drove through town with spray equipment, and made some pets sick..
Finally, in a last ditch effort to actually kill someone, they switched to chemicals and let them off in a subway. That's what it took.
Indeed, these things are much more frightening on paper than they are in real life.
And this isn't a valid assumption? ;-)
In a terrorist war, targets are symbolic, media presence is everything, and the goal is economic and political damage. Having the common people screaming for a police state to save us all just plays into the hands of the Communists, Socialists, and other "-ists" that will be delighted to see these terrorist get massive media coverage.