If you want to copy something, then copy it but be HONEST about it.

Say "Hey, I copied this because it seemed really relevant, and it expressed how I feel about ____ and what do you think?"

And then add a link back to the source. Better yet, just copy the first two paragraphs and say "for more information, read here (link)."

I've had about three cheetah comments, and they all pointed to my own blogs/web sites elsewhere. And that's how I responded to cheetah.