Over the years, I have known people who, rather than pay a high monthly fee for a home security system, simply buy a "Protected by" sign and plunk it down in their front yard. The hope is that the sign alone, will deter burglars and vandals. This assumes, of course, that the idiot burglar can even read the sign or even cares. Others, put up "Beware of Dog" signs for a non-existent dog, hoping for the same effect.
In that same vein, it seems we are spending $7 billion a year for the appearance of airport security without a system to really back it up. In a recent testing of the Transportation Security Agency, U.S. airports had a failure rate of 95% in testing that security. Realistic looking guns and bombs were used and passed through security undetected. Apparently, while the TSA agents were checking out a body scan of some great looking babe, testers were shoving guns and bombs through checkpoints like water through holes in a dam.
On top of that miserable result, we are apparently so proud that we discovered the major flaw that we published the results. So, now, not only does every American know it, so do terrorists. Does anyone think that ISIS let this little item slip by them unnoticed?
Why are we spending $7 billion on TSA?: http://www.cnn.com/2015/06/05/opinions/schneier-tsa-security/