Many years ago I had a near miss with a Marine Jet. He was traveling at 300 Knots, passed directly in front of us, close enough that we could see that the pilot was looking straight ahead. We should have tried to read his aircraft number. We were on flight following, but our controller failed to anticipate the jet's steep climb through our altitude on V 3. He did advise us that the jet was controlled by a military controller, probably Marine, as it dove to low level and departed to the south. He promised to keep aware of it, and warn us if it took any heading that might return, but it did not.
We requested the data for the jet from the FAA, they declined, as did the Marines. I sent a letter to my Senator, he was also stonewalled.
That should be much harder for the various controllers to do today.