The morning newspaper in Saint John, New Brunswick, Canada has a front page article about a German couple who immigrated to Canada in 1963. They have lived here ever since that time and now have received a tax bill from Germany going back to 2005. They have been sent documents saying that there will be penalties unless they pay $2331 retroactive income tax.
The article goes on to say thousands of German-Canadians have been getting these notices recently.
Inquiries seem to indicate a change of the law in 2005 in Germany making German pensions paid abroad subject to taxes.
I can’t post a link as the newspaper has moved behind a paywall but it really is starting to look like people should be citizens only of the country where they live.