FATCA agreement between Canada and the United States
FATCA was intended to catch tax-cheats, but ended up affecting all Americans living outside  of the United States. There are about one million Americans living in Canada. FATCA (Foreign Account Tax Compliance Act) was enacted in 2010, under the Obama administration. The agreement with Canada was concluded in February 2014 when Stephen Harper was Prime Minister of Canada. Americans include, for the purpose of this agreement, "accidental Americans", their non-American families and business partners, and former non-American residents of the United States.