Thanks to the tipster who sent in this picture, taken somewhere "on the top floor of Cannon in a construction zone." (h/t–JS)

The photo begs the obvious question: who put this there? The original Uncle Joe? Barney Frank? A staff prankster?

Send us your best guesses, total BS and informed truths.

Also, doesn’t the warning on the sign apply to the entire Beltway? Or just celebrity-filled black tie dinners?