People who litter.
Why can't they throw away their trash properly?
I've collected barrels of empty cans, bottles, coffee cups, fast food wrappers and associated trash from a section of my property along the road in the last 11 years. I would like all those litterbugs, especially the A&W Diet Root beer drinker, to have the image of the crying Indian in that old TV commercial permanently burnt into their nightmares forever!