This is the same group of people (a subset of Indians) who claimed PAKFA is awesome and stealthy and everything anyone could ever dream of, just a few years ago. The same group who thinks Rafale is about as stealthy as other 5th gen fighters because of SPECTRA without even understanding the basics of the nature of electromagnetic radiation.
I think it's just a distraction away from their own military blunders and embarrassments like their ship falling over to the side in the dock, forgetting to close the submarine hatch, LCA delays and unsatisfactory performance (even self-admitted by the boys who brought us two T-90 failures on the same day), Arjun embarrassment delay and unsatisfactory performance... the list goes on and one can see patterns developing. Threats and propaganda from these people ought not be ignored, but rather explained for the otherwise gullible and naive. Once the lies are dispelled and replaced by reasoning and open mindedness, we can leave it alone. So it's good to see some response at least over here. I've read the many many pages of Indians bashing China and Chinese people in the most despicable way only a sour loser group of individuals can. Happily there are more intelligent people here. Let's start with this. If they want to claim J-20 can be detected even at "a few km" they should at least give the name of the system that is capable. I am not aware of ANY decent Indian radars that's even capable of targeting small fast targets like ballistic missile warheads or cruise missiles, let alone stealthy aircraft from any useful distance. But then again, it's always been their claim (and hope) that J-20 is not stealthy at all. What a pathetic thing to think. Chinese overwhelmingly praised and respected the superiority of the F-22 when it came out. This is why we have progress.