It would be disastrous for many community newspapers. Many of the hebdos in Quebec, for example, rely on Canada Post, so it would be disastrous. For what I would describe as an urban daily, often they have their own carrier arrangements in large cities. However, especially in rural and remote areas, this would be devastating—there's absolutely no question about it—and that means those communities would be deprived of news about their democracy, and news covering police, school boards, courts, etc.
