Keep in mind these guys are smart, and strategic. Striking at a small, remote, low-populated area isn't out of the question either. The idea is that if they did so, they'd get the message across that nowhere is safe. You can go the big city, you can go to the remote farm lands, but they'll still get you, hence striking terror. That's the goal. So we need to keep our guard up on all fronts and assume nothing.