Maybe we should just come up with a list of banned items:
Guns, knives, ice picks, sharp and pointy sticks, rocks over a certain size, heavy movable objects like cars and trucks, cell phones, iPods and all MP3 players, home phones, kitchen timers, laptops or any type of electronics with batteries, electrical light fixtures, any primary liquid that could potentially be used in a binary liquid device (that includes all household cleaning products except dish soap), etc., etc.
That's just a partial list. Would that make you FEEL safer? The reason I ask is because if you stop and think for a moment that doing all that won't actually MAKE you any safer. But if you are into the feel-goodism of the 21st century this would take care of it.
Your list would make sense for Middle Easterners to be checked when they buy these a hundred at a time or more. The problem is that retailers have been remiss in reporting suspicious activity.