Let’s begin with this: In the long run (and the long run keeps getting shorter), even the biggest fortress can’t keep ideas out. Ideas move at the speed of light now, and they don’t need a carrier pigeon or an infiltrator to carry them. It’s okay to detest an idea, but it’s foolish to build a wall to protect against it.
Even though this is clearly and demonstrably true, fearful leaders want to do more inspections, insist on more pat downs, build bigger walls. Walls that won’t keep ideas out.
Source: Seth’s Blog