Hey, it gets even better. When a Luftwaffe Ju88G-1 of 7/NJG2 landed by mistake at RAF Woodbridge on July 13th 1944, their FuG 25A IFF system was compromised.

The British "boffins" developed and fitted a system called PERFECTOS to their Mosquito nightfighters. PERFECTOS sends a radio signal that triggered an automatic response from the FuG 25A - i.e. spoofing the German IFF into identifying itself and telling the RAF nightfighter where it was! This technique allowed detection and tracking of German nightfighters at ranges much greater than the RAF nightfighter's AI radars.

Numerous German nightfighter few prey to Moquito nightfighters of the RAF 100th Group equipped with PERFECTOS.

Much later, when the SRO-2 IFF system on the MiG-21 was compromised (by a defector), the USAF began equiping their EC-121 "College Eye" AEW aircraft in 1967 with QRC-248 which could track the SRO-2 IFF signals from MiG-21. Initially, QRC-248 only passively tracked the signals from SRO-2 sent when it was triggered by a North Vietnamese IFF interrogator. Later on, College Eye was allowed to use QRC-248 to actively interrogate and trigger the SRO-2 to respond. That was how MiG-21 were identified as "Blue Bandit" by College Eye.

Later still, a smaller system, "Combat Tree" was developed and fitted to USAF F-4D Phantoms. This system (APX-80) was used to good effect against MiG in the Arab-Israeli conflicts by the Israelis and during the Iran-Iraq War by the Iranians.