On a long ago trip to the Grand Canyon, I was appalled at the number of people who disregarded posted signs and stood in places they shouldn't, taking pictures.
Just because people have brains, doesn't mean they use them.
We visited Alaska a few years back.
Same thing. We went out on a glacier cruise and a whale-watching cruise on cold, choppy water with icebergs throughout. Both times, the captain specifically said, loudly and repeatedly, that nobody was to stand on the railing and risk being thrown overboard because they would likely die of hypothermia if they were in the water. Both cruises, NUMEROUS people received ass-chewings by the captian for climbing on the railing to pose for a photo!
IDIOTS! One was about an 8-yr. old kid. His mom was oblivious.