Having spent much of the 1990s devising and running airport/passenger/cargo security conferences around Europe, the US and Far East and dealing with the legislators, operators and equipment manufacturers at the highest levels, the "be seen to be doing something" attitude leaves me totally unconvinced.
The previous poster reporting the comment from a screener that explosive liquids can be effectively carried on board after being swallowed surpasses even the Heathrow T5 screener who, after first telling me the bag was too heavy and to big to go on board - it passes Ryanair's requirements - and this is the only time it has ever happened having passed through security at airports on every continent without having to unload the bag- insisted on not just hand searching my camera bag but putting each item in two trays, cameras and lenses in one, chargers etc. in another to go through the x-ray machine. When asked why, the answer was that x-ray machines can't effectively screen lenses if they are packed with anything else. He muttered some rubbish about the glass affecting the x-rays!!
There is no point in complaining, the shift managers will only make life even more difficult for you and delay you. All they want is for you to press the "satisfactory" or "good" button on the How was your Security Experience" machine. The TSA in the USA come in for a lot of criticism but Kennedy apart, I find them courteous and expeditious.
As far as charging for hand luggage goes, that should also be in the ticket price. An airline ticket should be for carriage of passengers and luggage from check in to to arrival gate so that ground handling, landing charges etc. are included. Security charges should be paid out of the departure tax that countries impose and which currently just goes into the general taxation pot.