When will terrorists get drones?

Scott Adams, creator of the Dilbert cartoons, raises this thought-provoking question.

In my book The Religion War, written ten years ago, I predicted a future in which terrorists could destroy anything above ground whenever they wanted. They simply used inexpensive drones with electronics no more sophisticated than an Android app...

So what happens when the drone attacks start happening in volume? Let's game this out. My assumption is that the coming inevitable wave of hobby-sized suicide drones will be unstoppable because they will fly low to their target and be so numerous that no defense will be effective. I predict it will be too dangerous to live above ground in Israel within ten years unless the trend is reversed. But what could stop the trend?

His question focuses on Israel, but of course it could be applied to any other place in the world. 

Via The Dish.