About eight years ago I wrote a book called The Religion War. The main premise of the book is that terrorists would someday use cheap, home-made drones, packed with explosives and navigated by GPS, to reach almost any target above ground. The FBI recently thwarted a plot of that sort.

As predictions go, that was an easy one. With so many terrorists in the world, the odds are good that at least one of them is a model plane enthusiast. The technology to make your own tiny drone is fairly accessible and the idea itself would be somewhat obvious to any nerd terrorist. And terrorists are copycats, so any scheme that works well once will become the go-to plot of choice.

The rest of the The Religion War deals with what happens in a world in which terrorists can blow up pretty much anything so long as it is above ground. We're about five years away from that.