I think the persistent issue is the identifying US/non-US partipants and the co-mingling of US/non-US participants within exchanges, and the need to understand

I think the persistent issue is the identifying US/non-US partipants and the co-mingling of US/non-US participants within exchanges, and the need to understand context to make sense of it. This seems inescapably fraught. And further complicated by their desire to still pursue Americans for inadvertently discovered crimes, resorting to parallel construction to avoid revealing questionably obtained evidence.