The F-35 is what gave the French a taste of their own medicine in its ability to continuously "gulp down" electronic emissions with no legal contracts covering it. And since in exercises anything you transmit is observable and therefore enforceable, while anything you absorb is unverifiable.
The Americans(and other NATO allies) were annoyed when Rafale's would do this in exercises and basically be "over-cautious" participants when in reality they were doing everything they could to capture whatever emissions(even those in training modes) from other participants. It was unmatched until the Lightening.
But that is like a Dyson vacuum - versus the black hole that is the F-35 which is like a flying Sigint station wherever and however it flies and transmits it across the fleet and system.
