Turns out to be folks who own, and probably claim to love, dogs. You may have noticed, among other cultural invasions, the sudden rise in folks who bag their dog's poop and then just leave the bag. Sometimes in someone else's yard. Sometimes on the sidewalk as if that is somehow, in some narcissistic alternative world, better.
But then it becomes more than just unsightly. Ruminants, including deer, have been found to ingest these plastic encased poop bombs. The results can be lethal. Maybe this is their intent. Maybe they think, that by culling the deer [over]population they provide a public service. Or, maybe they just don't think. Maybe they can't.