Not a traffic control radar.
I will have to think about the other question ... IFF is not my specialty ...
What is IFF? Governmental acronyms are enough to drive me crazy. lol
I guess I’m wondering if the difficulty that these terrorist groups would have in using these planes however they wanted to is that the planes have something (transponder or whatever...) that functions like a license plate - something that would identify them on radar as the stolen aircraft so that the FAA would immediately send the military after the aircraft. And if so, is there a way they can defeat that identification - like putting a different “license plate” on the plane or posing as a plane that doesn’t need to be identified beyond what it’s ordered to squawk so it doesn’t get into trouble because it’s got FAA authorization under VFR rules.