> The one detail I can't seem to find anywhere was what type of visa these SK nationals used to enter the US, and if they overstayed.

Because there is no visa process for short term professional work in the US, and never has been.

> A lot of countries are very careful to avoid letting you in on a tourist visa if you give off the appearance of entering to work.

That's just wrong. Virtually the entirety of the professional world travels around between industrial countries on tourist visas. Otherwise anyone going to a trade show is an "illegal" at risk of deportation.

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detaro 2 days ago | parent | next [-]

There's work and work. Most "tourist" visa will cover things like attending conferences or tradeshows, meetings with a different branch of your employer or customers etc, but on the other side more dedicated work, conference talks you are compensated for, ... can quickly be treated differently.

And if you don't come from a preferred part of the world even the former can quickly be quite a process to prove it.

	▲	ghaff 2 days ago \| parent [-]
		Exactly. Being nervous, of a "suspicious" ethnicity, giving any indication that you're being paid for being in the country, can probably all lead to issues. As I wrote elsewhere, aside from some countries that require a visa for any explicit business activity, a basic visa is typically fine to go to a conference or meet with a customer, much less send some emails.

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ehnto 2 days ago | parent | prev [-]

That is my impression of travelling to the US right now. Non zero risk of baseless detainment and deportation, and a non zero risk of being sent to a different country than the one you live in.

No thanks. I'll stream the conference online.