It is probably very silly to ban those small knives to be brought up to airplanes. There are so many occasions whereby you just need to cut something really tight while you are on the plane. Of course, its even sillier for the person who started terrorism. If it had not been terrorism, there would not be this ban either. The ban in Singapore was to prevent or rather lower down the risk of having a blood shed on the plane. My box cutter was confiscated because of this rule.