Yay, I'm bringing up a long dead thread. But I do have a point to make on it:
I hate these things. They stop the average person from carrying a anything they decide as wrong, such as a knife. I carry 2 knives on me almost all the time- a swiss card in my wallet, and a swiss army knife on my keychain. I occasionally carry around a huge swiss army knife, you know, the one with about 70 tools in it. The two smaller knives are laughable as weapons- they are more likely to make the threatened laugh than cower. The bigger one is a useful item in a fight- but only as a heavy object to add momentum to a punch. Congrats, you stopped me from carrying my mobile tool kit with me!
The intelligent, dangerous, and capable person can avoid these things easily. Terrorists can avoid these things easily, too. A knife fits nicely in an umbrella or cane, a gun can comfortably sit in a huge variety of generally metal objects without being noticed in a scanner. (A terrorist who shoots a gun off in an airplane is a moron, anyway) Explosive liquids? Well you aren't allowed to carry many litres of liquid or gel. You are, however, allowed to carry a pen. Pens are great for that. I can think of hundreds of ways to get past these things, and thats without expending money and time of an organization determined to do so. I just do it as food for thought.
September 11th came and people said to "do something" about airport security. They "did something". Something people notice, and realize they are "doing something". The only way to safely transport passengers by air without making a detemined person able to do harm is to make them strip down to nothing, put on a medical smock, frisk them, and send their baggage via a different plane. Otherwise it just annoys the innocent and sends the evil back to the drawing board for a month to come up with another way to bypass it.