I figured I'd throw in my 2 teef on the KFF subject:
Seems to me that if an opponent is trying to gain an advantage from YOUR wargear, then he's obviously a "loop-holer" as pointed out by SKEETERGOD. Crush him immediately...they will only keep coming back to try this again and again, somewhat like gamer roaches....
On the KFF. Remember the fluff: orky technology, or know whats/whatnots/shiney bitz, primarily works because they believe it will work. Look at the fluff pieces in our last codex. Imperial study of even basic weapons couldn't get them to work, because of psychic haromoncs. Non-orks don't have the wavelength in their biochemistry to activate the weapon, to get the vehicle to move that extra bit because it's red, etc. Why, then, would a KFF work for a non-ork, if they weren't an ally to begin with? If an ork believes you're an ally, then they'll believe that their red trukk goes fasta, that the zzap gun will work with a good thwack, and that the mek's KFF will protect ya's; even if it's only fer a bit.
So, if your opponent/enemy is trying to take advantage of your KFF, cry shananagans, look 'em straight in the eye, and krump 'em good.
Again, my 2 teef...got plenty left....