@hawkeye10,
Hawkeye if you could launch a hundred or two hundreds tiny drones against a soft target like the White House you might be able to destroy it with the right payload not four C but some form of incendiary payload instead.
There even been tiny GPS control prototypes drones able to cross the Atlantic with small weather instruments aboard.
This would make a new and interesting means of attack but far beyond the proven or at all likely capabilities of the entire Middle East terrorist networks together.
Also there are far simpler and far cheaper means of attacking even as well guarded structure as the White House.