It's all over the place, but I saw it most recently on
chez Zawodny's: liquids not allowed as hand luggage on airlines.
All liquids. The problem is that the average person is 90% liquid. And the average body has lots of cavities which, with a bit of ingenuity, can be filled with, who knows, TNT, anthrax, and even botox, one of the most dangerous toxines on Earth! Which will lead, I guess, to dehydrate people before boarding a plane, and then hidrate them back when they arrive on their destination. Which will also lead to huge space savings, you will be able to store tons of passenger powder in every plane! If that does not save the airline industry, nothing will.