Can a Russian, Israeli or Saudi or Mexican citizen in their respective country buy political ads targeting Americans and favoring or disfavoring a particular American candidate for office?
What if they are on vacation in the US?
What if they have jobs in the US, are not citizens, but live here and have an interest in politics?
What if they are here illegally and buy ads favoring or disfavoring a candidate for office?
What if in some cases it was their own money, what if in other cases they were hired by people in their home countries to buy ads?
What if they work in DC and act as foreign agents and pay for lobbying?
Does FB, Tw, etc. track all that?
Yes, lawfully [1]. This is a complicated area of law, which is why foreigners and foreign governments seeking to properly lobby in America hire proper counsel.
Yes. What’s so tricky about that?