I mean, you can't really blame them. If someone could potentially bring a disguised weapon on board a plane, then you want to bring the probability of that actually happening down as low as possible. After all, it didn't take that much to hijack the 9-11 planes. If that means seizing my water bottle even though everyone almost knows for certain that it's not a bomb, just to send a message to potential terrorists that they won't get away with hijacking a plane so easily ever again, then I'm all for it. Take my water.