## Thursday, October 15, 2009

### The Futility of Defending the Targets

http://www.schneier.com/blog/archives/2009/10/the_futility_of.html

Defending individual targets only makes sense if the number of potential targets is few. If there are seven terrorist targets and you defend five of them, you seriously reduce the terrorists' ability to do damage. But if there are a million terrorist targets and you defend five of them, the terrorists won't even notice. I tend to dislike security measures that merely cause the bad guys to make a minor change in their plans.

And the expense would be enormous. Add up these secondary terrorist targets -- stadiums, theaters, churches, schools, malls, office buildings, anyplace where a lot of people are packed together -- and the number is probably around 200,000, including Beaver Stadium. Full-time police protection requires people, so that's 1,000,000 policemen. At an encumbered cost of $100,000 per policeman per year, probably a low estimate, that's a total annual cost of$100B. (That's about what we're spending each year in Iraq.) On the other hand, hiring one out of every 300 Americans to guard our nation's infrastructure would solve our unemployment problem. And since policemen get health care, our health care problem as well. Just make sure you don't accidentally hire a terrorist to guard against terrorists -- that would be embarrassing.