I get it, but it's still a stupid law that punishes the average iranian citizen that has nothing to do with the iranian government. I recently lost a job offer in a semiconductor company because of the deemed export law. And by "a foreign person" they actually mean chinese, iranian, syrians and cubans. Most technologies aren't restricted to most of the world including Saudia Arabia and Pakistan the origins of almost all terrorists.

"how on earth does one hire Iranian citizens" You can't hire anyone from an embargoed country without obtaining a deemed export from the government which is a very lengthy and complicated process. I'm from an embargoed country and I recently lost job offer in a big semiconductor company because of the deemed export requirement. To avoid any export control liability, some tech companies prescreen applicants before extending interview invitations. If you google, there are a couple of articles where lawyers advise companies to prescreen based on country of origin, arguing that it doesn't violate anti-discrimination laws.