Well I haven't systematically recorded the instances and cross referenced it against the prevalence of dog presence, obviously. Nor do I feel the need to. It's

Well I haven't systematically recorded the instances and cross referenced it against the prevalence of dog presence, obviously. Nor do I feel the need to. It's ubiquitous and absolutely not accidental, at least in most cases. The only two possible explanations I can think of are that a) people are under the impression that forests have janitorial staff that will collect the bags or b) they believe that the bags will somehow keep the environment "cleaner" by containing the germs?