Just because a law is hard to enforce (especially on individuals), doesn't mean that it COULDN'T bite you in the ass (especially if you're an employer).

Vacation visa (B-2): no work at all. Period.

Business visa (B-1): Work for a specific purpose, nothing that could be construed as "putting an American out of a job" (because that's what politicians care about).

USCIS does not fuck around with this. If you want to even VOLUNTEER in the USA you will need a J1 visa in many cases.

Q: if you earn income in a country, whether legally or not, are you liable for income tax to that company's tax authority?

A: Generally Yes (of course, the tax itself may be offset by foreign tax credits or other exemptions)

B: If you earn wages, is your employer liable for employment taxes where you earn it?

A: Also yes, with the same caveats.

It all comes down to enforcement and whether it's worthwhile for the tax authorities to go after you. But generally, employers make better targets than individuals. An individual (a) has less money, and (b) may just say "well I just won't ever go back to the country where I owe money." A company doesn't have that luxury if it wants to retain its clients in that country. Also, companies make juicer ATM's for tax authorities to penalize and collect from.

And that's just the tip of the iceberg. Wait until you learn about data protection regulations - and the (often stricter) terms that clients sometimes dictate.

Source: work for a small head count multinational and have dealt with some of these situations regarding foreign national employees and "workcations." Maybe we could get away with it. In fact, we PROBABLY could get away with it.

But we strictly don't do the "fuck around" part, because we don't want to get bit by the "find out" part.