As an American residing abroad, and married to a non-American, I tend to get a lot of trouble from FATCHA and the like. These laws effectively force me to put all savings in my wife's name because that's the only way I can deal with banks in Europe.

Now we have these kinds of issues in the US. But proving citizenship isn't trivial. When we were in the US, my wife, to my knowledge didn't have to prove citizenship, only provide ID (such as a driver license) and a social security card (which also doesn't prove citizenship). Of course they can't just ask everyone for birth certificates or passports on short notice. So they just ask for verbal answers? Really?

But there is more. Why is there this focus on dual citizens? And why are banks being asked to effectively surveil people for dual citizenship?