This is one of my favourite "goofy proofs" for KJV-onlyism (probably second only to proof by time travel) because you see it fairly often, and it's almost always a source of fine unintentional comedy.
Proof by "monkey see, monkey do" occurs when a KJV-onlyist attempts to turn the tables on his opponent: substituting "KJV" for a key term in the original argument, he throws it back at him, then leans back and waits for him to go completely to pieces at such a clever retort. Unfortunately, rather like a trained monkey, the KJV-onlyist usually didn't understand the nature or purpose of the argument being made, so these would-be show-stoppers usually end up being unintentionally hilarious.
Here's one of my favourite examples of "monkey see, monkey do." Several years ago on the BaptistBoard, a poster named "Swordsman" began a thread titled "Is the KJV of God or man?" He remarked, "I thought that this question should get to the root of the version issue." More recently, on the Bible Versions Discussion Board, another Riplingerite KJV-onlyist named Keith Whitlock pulled this classic out of his hat as well.
It's easy to see where it comes from. The question alludes to the one Jesus posed to the priests in Matt. 21:25, when they challenged his authority:
And when he was come into the temple, the chief priests and the elders of the people came unto him as he was teaching, and said, By what authority doest thou these things? and who gave thee this authority? And Jesus answered and said unto them, I also will ask you one thing, which if ye tell me, I in like wise will tell you by what authority I do these things. The baptism of John, whence was it? from heaven, or of men? (Matt. 21:23-25 KJV)
The priests talk amongst themselves, and realize that Jesus' question has trapped them:
And they reasoned with themselves, saying, If we shall say, From heaven; he will say unto us, Why did ye not then believe him? But if we shall say, Of men; we fear the people; for all hold John as a prophet. And they answered Jesus, and said, We cannot tell. And he said unto them, Neither tell I you by what authority I do these things. (25-27 KJV)
Jesus had impaled the priests on the horns of a dilemma, and they knew it. Either alternative forced them to admit that John the Baptist carried a lot more authority than they did, and they didn't want to acknowledge it.
"Aha," thinks the KJV monkey-boy. "All I have to do is take out 'the baptism of John' and replace it with 'the King James Bible'! Then I've got those godless Bible correctors over a barrel for sure!" The only problem is: Jesus had the priests trapped because his question exposed an inconsistency in their thinking. But the question doesn't make that dilemma; it only works if there is a dilemma to be exposed.
Non-KJV-onlyists stand to lose nothing here. The KJV came from God: it is a faithful and accurate translation of the God-breathed Scriptures. The KJV also came from men, because translation is a human work, and because the quality of the translation sometimes shows up the limitations and fallibility of human knowledge where the Scriptures are concerned.
You can't just slap a "KJV" into a good argument and automatically expect to get another good argument. You have to understand the context of the original argument, and how it may or may not apply to the current issue. Unfortunately, as we see all too many times, KJV-onlyism and context are rarely on speaking terms.