Agence France-Presse: Authorities arrested 16 people Sunday after Greenpeace activists scaled three smoke stacks at a Shell operation in their latest action protesting the exploitation of Canada’s vast oil sands. Activists from Canada, France, Australia and Brazil occupied part of an upgrader machine Shell is building at its Scotford site in Fort Saskatchewan, Alberta to convert oil sands into fuel, the group said in a statement. By the time the protest ended Sunday authorities detained 16 members, …