When my friend Brian told me the American tax police were after him, I thought he must be nuts. Brian is a worrier. He gets a little paranoid sometimes. “We haven’t filed a U.S. tax return in 20 years,” he said. “Now our accountant says we have to – or else.” Brian and his wife are from the States. He took out Canadian citizenship years ago. They’ve lived and worked in Canada for decades. They have no U.S. income or assets. They are 100-per-cent tax compliant – in Canada. “Forget about it,” I advised. “What could they possibly do to...