would like to introduce you to bruce schneier who will be talking with us about restoring sanity to airport security. thank you, bruce. [applause] >> good afternoon. let's start by reviewing the past 20 or 30 years of airport security and we take away guns and bombs in the terrorist used box cutters. we took away rocks cutters and knitting legals and they put in explosives and their sneakers. we screened footwear, they tried liquids. we limit liquids they hide a bomb in their underwear. we use full-body scanners they hide a bomb in a printer cartridge. we now believe it or not banned printer cartridges over 16 ounces and they are going to do something else. this is actually a stupid game and we should stop playing it. it is not security, it is security theater. now this conference is primarily about body scanners so let's talk about them for a minute. the purpose of body scanners is to detect petn. this is what it is all about. petn is a plastic explosive. is what the shoe bomber used. is with the liquid bomber used. it was what was in those yemeni printer cartridge mail bombs. it is in ira