After the 9/11 attacks, airlines and public buildings adopted a flurry of "security" measures, like taking away pen-knives from fliers or requiring visitors to office buildings to be photographed or present a driver's license.
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Bruce Schneier's seminal 2003 "Beyond Fear" called these measures: #securitytheater.
Schneier pointed out that these measures would be easy to circumvent, and were thus providing only the comforting appearance of security - not security
Security theater is worse than nothing. Security theater gives people the false impression that their risks have been mitigated, when actually things are just as dangerous.
After al, if you know that danger exists, you can take some steps to mitigate or avoid it.
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But if you have the false impression that you've been made safer, you might unwittingly engage in risky behavior.
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Like, if you know your car's brakes are flaky, you might nurse the car along to the mechanic at low speed on side-streets.
But if you don't know about the brakes, you're apt to discover their flaws at 75mph on the freeway.
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