Chalk up another way idiots can spoil things for the rest of us: People use hotel coffee pots to cook methamphetamine. From the article:
Phillips says it's pretty easy to tell if a coffee pot has been used to cook meth. It will have a dark reddish-orange stain. You should also be skeptical if there's a chemical odor when you walk in the room.
Thanks to Stuff from Patti Shock for the pointer.