Some probably did not, but it was common to ignore the law. There does not seem to be a process for getting valid visas for this kind of project:

https://www.ft.com/content/c677b9aa-2e89-4feb-a56f-f3c8452b3...

And they would feel betrayed because their bosses probably told them it was ok.

It sounds like they had valid visas (or ESTAs), the question is whether they were allowed to do what they were doing on those visas. That question potentially has 475 different answers too, because there are certain sorts of what one would commonly refer to as "work" that are permitted on an ESTA or B-1 visa, so one would need to know the exact things each individual was doing to make an individual determination.

As for why they're pissed off, that seems obvious. If say Australia wanted to have a software engineering office, invited my employer to set up an office, my employer sent me over there to do something related to that telling me it was in accordance with the law, and then the Australia government arrested me, threw me in jail, and posted videos of this all over social media, I would be pissed off too.

I think what ICE is doing is bad, but I do feel a bit annoyed with how the media is reporting this. They WERE misusing the B1 Visa a bit - at least that’s what the facts point to, and that’s the only reason they are sending workers back to Korea.

I understand why they did this (H1B is painful and a B1 visa may have been the only way to get people to train American factory workers), but it’s not like they were completely innocent. South Koreans were still treated with a lot more respect and dignity than almost any other ethnicity has been.

Visas can come with a bunch of rules attached to them about what you can or can't do in the host country, and those rules can get kind of tricky to properly interpret.

> why they would feel betrayed

South Korea is essentially a U.S. vassal state, so there’s an expectation that ICE wouldn’t be as brutal to them as say, if they were Venezulans.

I don't know much, but a little bit of critical thinking can easily help you understand what's really going on.

1. All these plant construction deals have due dates both on paper and off the paper. Build these by x date kind of deal in order to get x amount of support or tax cuts or regulation burden eased etc in these states. So these companies are trying to build these things ASAP.

2. Also these due dates are off the paper. When new leaders come in at federal, state or municipal, it always carries risk that some things will change and construction of it becomes difficult. Projects of this scale can be scrutinized and delayed to death because they are "illegal" because it can't fully satisfy million lines of legal clauses. It is possible because the political climate allows it. Even from Korea side, imagine new regime comes in from Korea side that tries to build ties with China, and they say we are reducing ties with US and you should ease development etc. These companies are then in negative by order of billions.

3. So time is of essence.

4. H1B would be the visa to get for these workers but it is gamed to death and these workers can't get them in time.

5. So both America side, and Korea side agree in an underhanded way to agree that these workers can come into work, build the plants and train the local workers ASAP.

6. Look at the recent interview by Trump where he even admits it is expected that workers need to come in fast to build these plants. So he's understanding of the situation. He's been a builder for his life. He know projects of these scale require a green light from the authority to work.

7. Trump is likely using this incident as a bargain chip for trade negotiations or ICE accidentally going pitbull on an unintended target