If such craft are in the hands of private contractors, I would think that there would be big money to be made if the contractors could patent any of the technologies they may discover.
It's like when a wife accuses her husband of having an affair and he denies the affair but refuses to let her see his phone and/or credit card statement.
Lockheed Martin and its "black" subsidiaries are said to be the main beneficiaries of such transactions.
Try watching this:
Sean Ryan podcast with USMC Michael Herrara
https://www.youtube.com/watch?v=3zm4nh3S66I&list=PL4pqo9Uoh0WuUKxw0BmaK1yrg9Kd7E4lk&index=38
and this:
Sean Ryan podcast interview of DC Long former US Army.
https://www.youtube.com/watch?v=8ebGlEFac6k&list=PL4pqo9Uoh0WuUKxw0BmaK1yrg9Kd7E4lk&index=37
These are both ex military men who had encounters with unknown technology. I would highly recommend checking out all of Sean Ryan’s podcasts on his channel. He is a former Navy Seal/CIA/private contractor. He does extended sit down interviews with a lot of ex military people. People that will not speak to other “journalists”. He also did an interview a couple weeks ago with Sarah Adams former CIA officer who was on the ground in Benghazi when it was attacked on 9/11/2011.
After watching the three video interviews I sent you on the previous post I surmised that the stealth technology invented by Lockeed Martin and or Northrop Grumman was probably reverse engineered from alien craft.