NO, I understand what you are saying now, and I said earlier that I wasn't experienced enough to judge what people are seeing on this display.
I was responding in part to Rokke's comment, "I guess it really doesn't matter if you ignore the fact that the radar can only "track" transponders and therefore, if it was "tracking" something real, whatever it was, was squawking an IFF code."
Radar can surely track passive objects as well as transponders. Transponders make things brighter and easier to track, but they are mainly used for purposes of identification. Perhaps the original ATC radar and the display people are looking at are two different things, but that's not entirely evident from what is being said here.
Anyway, I'm headed for bed.
No problem, it can be confusing at times.
That's not entirely accurate. Transponders are transmitters. They don't add anything to a target's radar cross section. They emit an electronic signal providing a "secondary" contact for radars tuned to look for that signal. A "secondary" contact is not a raw radar return. It is simply a radio signature transmitted from the target aircraft. And while you are absolutely correct to say radar can track passive objects, the system everyone is viewing in this thread cannot. It can only see "secondaries".