I was looking at this Facebook job description based in the US and read:
Please indicate whether you are either a citizen or lawful permanent resident of any of the following countries: Cuba, Iran, North Korea, Syria or Sudan.
 Yes  No
NOTE: Facebook is asking this question, and will use your response, for the exclusive and limited purpose of compliance with federal export control laws and regulations.
What's the repercussion of being a citizen or lawful permanent resident of Cuba, Iran, North Korea, Syria or Sudan when applying for a job in the US?