Defining "security theater"

Security theater consists of security countermeasures intended to provide the feeling of improved security while doing little or nothing to actually improve security. The term was coined by Bruce Schneier for his book Beyond Fear, but has gained currency in security circles, particularly for describing airport security measures. It is also used by some experts such as Edward Felten to describe the airport security repercussions due to the September 11 attacks. Security theater gains importance both by satisfying and exploiting the gap between perceived risk and actual risk...

In many cases, intrusive security theater measures also create secondary negative effects whose real cost is hard to quantify and likely to dwarf the direct expenses. Such ripple effects are often connected to fear; visible measures such as armed guards and highly intrusive security measures may lead people to believe that there must be a real risk associated with their activity...

Via The Seminal.