The US is well aware these aircraft could end up in the wrong hands. For that reason, the Iranians, Chinese and Russians will gain little from this. Stealth technology is not new and started in the 1940's. The US even tried to take over where the Hitler regime failed to no avail. It wasn't until the 1980's when the US had the technological capability to make the stealth work. So party it up but US technology is still light years ahead of Iran. If they think this evens the playing field, they are in for a RUDE AWAKENING!
Wreckage found on Reunion island triggers speculation over missing MH370 (DPA)
from the article: Iran state television displays 'downed U.S. surveillance drone'