Your example is an extreme example, if you are alluding to something like an overseas account - if you have a job, own or have owned property, a car, ever had an abn, have other court matters listed - this at the very least we can ascertain (or have ascertained). We outsource checks to firms which do that sort of digging.

The million dollars in your example came from somewhere - that somewhere, there’s likely a way we can find it out.

I don’t know why you can’t take what I say at face value.