I'd also say sign fatigue (plus general fatigue) is a thing. When you go to an airport security line there's like these giant signboards stood up like the 200 Commandments, each with a mix of pictures and walls of text of for things you're not allowed to bring on a plane. Or some things you can check and not carry on or you can carry on and not check. And you're also expected to know all of that while you are in transit, stressed, and maybe also sleep deprived.

Too many signs to properly pay attention to them all.

Good luck ignoring bullshit signs when going through airport security and customs. Let us know how that goes for you

You sound pleasant.

You've been here. So you've witnessed first hand our lack of social cohesion. We're not a civilized people. We're barely above feral and deeply ensconced in tribalism. Capitalists did a great job gaslighting this country into this situation where we're aware of their abuse but somehow still manage to blame one another instead of the abuser. The Business Plot didn't fail, it bided its time and rolled out slowly and surreptitiously.

Canadian ex-infantry checking in with an exception to that assertion.

I definitely haven't been shouted at in any of the European airports I've been in (from memory, KEF, HEL, AMS, MAD, BCN, NCE, and BER, so not super representative of the continent), so to me, it seems like an American phenomenon. I haven't been to Canada enough to know what it's like there. It's also somewhat recent. I've been flying for 25ish years now, and I feel like the yelling has only been happening for the past, I dunno, 5-7 years?

As others have said, I don't think it's that we like being shouted at. We just have a large number of people who are, uh, "ruggedly individual," to put it in nice terms. Those people don't really think about others enough, so you have to yell at them to get them to pay attention to the world around them. I'm the type of person that looks up the rules before I leave and makes sure I have all of my shit out of my pockets before I even enter the security line to ensure I don't reduce the efficiency of the security checkpoint. I often feel a bit exasperated with the people who don't think about others in those situations.

As a means of dealing with it, I've found that smiling, making eye contact, and nodding at the TSA agent doing the yelling makes them less likely to yell at me while simultaneously making me feel a bit less frustrated—expressing nice feelings and trying to show some common humanity with the people I'm interacting with makes it harder for me to feel angry. Not saying that'd work for everyone, but it's helpful for me.

So they can rob noncitizens using asset forfeiture laws. Never travel in or through the US if you need to transport large sums of money or valuables.

Actually, the better advice is never travel in or through the US. I wish that were an option for me.

A couple of times I've travelled Air NZ route that goes London-Auckland via LAX. The plane has to stop to refuel I guess. All the passengers are forced to queue up to be fingerprinted and have their eyeballs scanned, while a security guard walks up and down screaming "STAY IN THE LINE!" Then they're herded into a lounge barely big enough to hold everyone (first class passengers have their own little pen next to the toilets). Apologetic air crew distribute apples, crisps and bottles of water. For hours. Through a glass wall is a view of the rest of the airport: shops, cafes, bars, space to stroll. But hey, at least you get to not miss your flight, and the US is safe from Kiwi tourists.

I don't know if they still do this, I avoid the route.

Because fuck you, that's why.

Also, freedoms or something, I dunno.

I only stopped there for transit on a flight to Mexico. Just before boarding my flight I was told that I need a visa for the US, which is extremely weird because normally airports have transit zones where you don’t need any visa. But apparently the US is special, so you actually have to enter the country before going right back into the airport. This nonsense made me miss my flight.

Not like that, they didn’t let me board my flight from Europe to Texas. Even though I had a connecting flight to Mexico few hours later.

I am no longer on your side. if your journey is :

European country X -> Somewhere in the US -> Texas -> Mexico

Then of course you're going through security controls, etc etc. You're going from the international processing and flights part of the airport to the domestic flights part of the airport, which is the zone where any asshole in that country can travel in, so you're properly entering the US. Of course you need proper clearance and visas and all that.

I initially assumed your journey was

Non US country-> Somewhere in the US -> Mexico

which you'd be completely right