SEE CONTEST UPDATE BELOW
A friend walking through Beijing's (lovely) Ritan Park last week sent this picture of a warning sign there. I know it means "Don't do [something]," but what the something is I couldn't say.
Update: Ah, I think I've now guessed what it is. Once you "see" it, it's "obvious." Sort of. It's much easier if you've lived in China than if not.
Gala prize of an Atlantic subscription to the first reader who doesn't already know, and doesn't ask a Chinese person, but can figure out through semiotics what the sign might convey.
CONTEST UPDATE: We have a winner! It's Alex Woods, whose birthday it also is today. Happy Birthday! Several other people have also written in with the correct answer.
Announcement of the "real" meaning tomorrow, plus a variety of amusing (if inaccurate) guesses. Eg, "Don't get caught in the zipper." Feel free to keep sending them in.
After the jump, another recent pic of a warning sign in Beijing. This one appears to mean, "no car bombers."
From Guanghua Road in the Central Business District of Beijing, last week. Whatever the sign means, it certainly looks like a nice day!