I’m not certain but I would bet that late-model Stingers will not operate in the US.
So the use of a Stinger to bring down an airliner in the US seems unlikely to me. I’d worry about all the old Soviet stocks of obsolete man-portable anti-aircraft missiles more.
As an embedded system person I can easily build devices that will only operate in certain geographical locations... I’m certain that military contractors can build similar systems.
It does not not necessarily depend upon GPS, it can rely on RF fingerprints or satellite assets other than GPS.
“I’m not certain but I would bet that late-model Stingers will not operate in the US.”
They are IR-guided, not geo-limited as they have no GPS or other location tracking capability, embedded or otherwise.
They are a simple man-portable, IR tracking device with a motor and contact/proximity fuse. . .point. . .IFF. . .lock. . .launch.
A lot of the hand held have a short shelf life on the warhead. But if a object is moving at m-2 or better hits you it is still going to do major damage. Always remember if bad things happen in flight you can not pull over to a cloud and get out and fix it.