This story happened in China. I don't know about China, but maybe their airport security is not as bad as U.S.
Personal story: Bringing liquids to airplanes is not allowed in Iran. I remember on our flight back from Shiraz, we brought about 8 liters of rose water, orange blossom water, etc. with us. The security saw it in the screen and asked what the liquid was. "Herbal water", I said. He nodded and called, "Next". Didn't even open the bottles to make sure.
Also many people bring back several liters of water from the holy Well of Zamzam[1] in their flight back from Mecca. The record I've heard of was 40 liters.
They follow the American protocols, and then some.
Last time I was there, after handing my bags over I got called to the inspector's room. They'd x-rayed my bags and seen a cigarette lighter [1]. I have no idea how they recognized it as such, but they pointed to the area in my bag where it had been seen, and asked me to open the bag and remove it.
On another flight, we were all waiting in line to check-in, but the agents hadn't shown up. Somebody gave up on waiting, and just left their bags sitting in line - this while the recording about unattended bags was playing (yes, they've got that in China, too). It was funny to watch everyone in the line studiously ignoring the unattended bag, for fear that they'd shut down the terminal while calling the bomb squad, and we'd all miss our plane.
[1] I don't smoke, but it's in my first aid kit for sterilizing a needle.
What about domestic flights? Some domestic airports like Melbourne have the lounge outside the checkpoints, and even if they are through them domestic security in Australia is very quick and easy.
it gives people the illusion that they're safe even though the actual incident which prompted the creation of the TSA and DHS has been ridiculously under-investigated and official conclusions' are full of holes.
I've never flown domestically in China, but I remember security being worse than in America. I remember having to take my shoes off before it became standard in America and having to go through security a second time right before getting on the plane where all the drinks I bought after security had to be thrown out.
My anecdotal experience at Guangzhou (2 months ago), flying internationally, was the opposite. Didn't have to remove shoes, didn't have to take my laptop out of my bag. I was going to remove my belt before going through the metal detector but they told me not to, which set off the alarm. All they did was wave a handheld metal detector over my body and then I was through. Didn't get patted down and didn't have to go through a body scanner.
I flew from the airport in question to Shanghai a couple of months ago.
Security wasn't unpleasant, but it took a while, there was a long and slow moving line. We had to discard lighters and show passports, but the latter is par for the course in China. It feels like the Chinese are slightly more overbearing with foreigners, which helps, since there's a huge language barrier.
We where lugging a flight case of cymbals, which got quite a lot of attention and laughter from the operators going through the x-ray.
Not if you tell them you're just going to eat. Seems like that's pretty easy to confirm. Why be sneaky about it? Obviously nobody at the airline lounge cared that this guy showed up every day, why would the guards care?
Imagine you're a guard there and I drop by every day for a meal. You're wondering if I'm a a terrorist looking for security holes while I eat, and your biggest concern is false negatives: you would hate to rule me out as a threat and then find out I blew up your airport. What questions would you ask me to figure that out?
There's a reason you don't often see phrases like, "Can't prove a negative," used by people whose job is to evaluate security risks. The relevant way of approaching problems like these tends to use a lot less Boole and a lot more Bayes.
So, same question, and this time really think about it: you are capable of keeping an eye on a limited number of potential threats, you can never completely disprove that any individual means you harm, but you have to look as carefully as you can at the most plausible threats in the time you have available. How suspicious is my behavior, and what evidence would it take to convince you that my threat is negligible? What about the idea that you might personally be blamed if you cleared me and I later turned out to be a terrorist: does that affect your calculations? If so, is that in the best interests of the airport, or just you personally?
That assumes that on-scene guards ask questions of the subject before reporting observed suspicious behavior (which may or may not be the case, and is even less likely the case in the event that the "guards" that observe the behavior are automated face/gait/etc. recognition systems looking for unusual patterns.)
