Not much else to add here but....
I've never run across this, but I have wondered if it has ever happened to others. I guess that answers my question. I have to think this is an isolated incident right now though.
I think it's completely unacceptable. Like WildWoodKe said, I have left some Waymarks out of certain categories, and in some cases, I may have some that will fit into other categories that I'm not aware of. If someone comes along, takes their OWN pictures, coordinates, writes up their own description, and tosses it into another category then that's great. But copying and pasting someone else's work IS plagiarism, and wrong.
I'm not sure that there needs to be a guideline against it, since I think for most, it's a common thought that you have to do your own work to get credit. Looking forward though, I wonder if it would cause problems if someone does that and uses the defense that "it's not in the guidelines...leave me alone, go away."