Unknown fans of the classics painted the Rock today with the ominous “Cave Ides,” most likely a reference to “Beware the ides of March” (the 15th of March), as told to Julius Caesar in the Shakespeare play.
UPDATE: The mysterious painters seem to be associated with Eta Sigma Phi, the national honorary collegiate society for students of Latin and/or Greek. More information can be found at their Web site. Thanks to Tracy for this information.