Escalator safety is simple

In the MTR (subway) stations here, they have a series of announcements about escalator safety. All begin with "Escalator safety is simple...." and there's something about the words and the tone of voice that when I hear them, I automatically mentally respond, "Is it now? Why, thank you."

Anyways, most of the safety tips involve holding the hand rail and using the elevator instead of the escalator if you have luggage. Recently, however, I've heard a new one that really makes me wonder what happened to prompt the addition:

"Escalator safety is simple. When wearing sandals, keep your toes away from the edge."