People have occasionally asked me "What is the most effective warning sign that I've ever seen?"
I'm not sure about effective, but there is one sign that is certainly the greatest attention-grabber.
I was walking down the street one day in Singapore and passed a rather anonymous-looking building. There was a gate with the warning sign below.
It made the consequences of ignoring the sign fairly clear! Considering the Medieval nature of many Singapore laws, I could only take this sign at face value.
I figured that no one would believe that this sign exits if I didn't take a photo of it. I started taking the picture when a man came running out of a door and screaming at me.
I was going to tell him that there was nothing in the sign about photographs, but discretion suggested that I just click the camera and leave.
I wouldn't have wanted to be the model for a new sign about the consequences of taking a photograph.