Obviously this is not the same thing, but the question sounds pretty similar to the relatively-new IRS requirements for reporting foreign assets (and those requirements raised the same question in me: is stock of foreign companies included?)
At least for the IRS, they're only looking for serious international men-of-mystery.
http://www.irs.gov/pub/irs-pdf/i8938.pdfAssets Not Required To Be Reported1. A financial account that is maintained by a U.S. payer, such as a domestic financial institution. In general, a U.S. payer also includes a domestic branch of a foreign bank or foreign insurance company and a foreign branch or foreign subsidiary of a U.S. financial institution.
Examples of financial accounts maintained by U.S. financial institutions include:
U.S. mutual funds accounts;
IRAs (traditional or Roth);
Section 401(k) retirement accounts;
Qualified U.S. retirement plans;
Brokerage accounts maintained by U.S. financial institutions.