Puzzle of the Day "If we do not wish to fight, we can prevent the enemy from engaging us even though the lines of encampment be merely traced out on the ground. All we need to do is to throw something odd and unaccountable in his way. Tu Mu relates a strategm of Chu-ko Liang, who in 149 B.C., when occupying Yang-p'ing and about to be attacked by Ssu-ma I, suddenly struck his colors, stopping the beating of the drums, and flung open the city gates, showing only a few men engaged in sweeping and sprinkling the ground. This unexpected proceeding had the intended effect; for Ssu-Ma I, suspecting an ambush, actually drew off his army and retreated." What does this paragraph say to a system administrator or security officer seeking insight to defend her systems?