v. To recklessly disparage a much larger and more powerful rival, particularly a business competitor.
1999
But Novell has been cautious not to flaunt its success. The mantra at the Utah software maker is to make nice with Microsoft, or as Chris Stone, Novell's senior vice president of strategy and corporate development, said: "Don't moon the giant."
1998 (earliest)
Trojan horse strategies depend on the enemy being asleep. If you moon the giant or awaken the enemy, you might get burned.
The verb to moon means "To expose the buttocks in public as a prank or disrespectful gesture," You might be interested to know that the Random House Historical Dictionary of American Slang traces this sense all the way back to a 1958 film called "Beatniks" in which a character named Moon says, "One more word…and I'm gonna moon you."