Canada has signed an inter-governmental agreement with the US, implementing FATCA in Canada. As a result, more than 155,000 Canadian tax records were delivered from Canadian banks to CRA, which in September 2015 turned them over to the IRS, circumventing Canadian privacy legislation. Most of the holders of these accounts are ordinary Canadian citizens, whose only crime (as Mr. McKenna notes) is being born in the US to Canadian parents or who otherwise have only tenuous connections with the US. Under the agreement, the Government of Canada plans to turn over Canadian financial information to the IRS annually.
This agreement was implemented by the former Conservative government, over the objections of opposition parties, including the Liberals. Now that the Liberals are in power, they reversed themselves and now insist they have no choice but to obey US demands.
The Alliance for the Defence of Canadian Sovereignty (ADCS) has launched a lawsuit against the Government of Canada, opposing this agreement. The plaintiffs are two Canadian women born in the US to Canadian parents and brought back to Canada age 5 years.
For more information, see the ADCS website: http://www.adcs-adsc.ca/