No fool like an April Fool.
Answer a fool according to his own folly.
The original handwriting on the wall: Mene, Mene, Tekel, Parsin.
You have been weighed in the balanced and found wanting.
Cynthia's handwriting, "A nation of sheep begets a government of wolves."
Variously attributed to Bertrand de Jouvenel and Edward R. Murrow.