Another Incident at Yellowstone

I'm constantly amazed by the number of Yellowstone visitors that think its a petting zoo. I watched a guy walk up to the south end of a north facing male elk with a full rack of horns, and slap him on the rump so he could get a picture of the elk's head. The elk just started grazing again.
Earlier in the day, I watched a young lady attempt to drive through a herd of Bison as they were crossing the road to a different pasture. She was complaining to a ranger because one of the bison head butted her driver's side door. BIG dent.
I don't think I could be a ranger there without punching somebody's lights out nearly every day.