Thank you for the question.
The constitutionality of this is an issue of expertise that really goes beyond my pay grade. There are privacy and discrimination concerns raised.
I'd like to just state, however, that we should remember that we do not have an anti-discrimination provision in the IGA. So absent an IGA, there would have been nothing to stop a Canadian institution from deciding not to implement or comply FATCA, but instead to become non-compliant, and thereby have choices that they do not have because of the IGA. The IGA says Canada will make all institutions comply with FATCA whether they want to or not. So a choice has been taken away, whether that was a good choice or not. No cost-benefit analysis was done on any of those.
So we could ask about discrimination and privacy. Those are important questions, but I think we should also be asking where the analysis is of what the cost benefit has been, and whether this is legally acceptable, not just under the constitution but under the Income Tax Act.