When Will Terrorists Get Drones?

Ten years ago, Scott Adams wrote The Religion War, a novel that "predicted a future in which terrorists could destroy anything above ground whenever they wanted." He thinks it's starting to come true:

Hamas has its own drone production facility, or did, until Israel found it. One presumes Hamas will build more. How long will it be before Israel is facing suicide drones that only cost its enemies $100 apiece, fit in the trunk of a car, and can guide themselves to within 20 feet of any target? I'd say five years.