Michael Power would like to introduce you to FATCA (Foreign Accounts Tax Compliance Act).
Don't blame the messenger; Michael's a nice guy:
Michael Power - It’s Time You Met FATCA
... So affected institutions (remember FATCA covers both financial and non-financial entities) must identify clients who are American (which means asking the question of every client since “U.S. persons” do live abroad); obtain their consent to the disclosure of sensitive personal information to the IRS or withhold the provision of a service for a failure to provide consent to disclose. How these organizations reconcile FATCA compliance with PIPEDA compliance is a topic for another day.