You don't know. I don't know.
That's why this hearing is being held. No one seems to know what we are dealing with...but the DOD wants no one to look into the matter.
If there's nothing to see, why bother to prevent people from looking. Just ignore it and it'll go away.
From an article I linked to :
“A lot of those people think that there are actually aliens behind UFOs, and so they think it’s a very important thing for people to know about. So they’ve been working, sometimes overtly and sometimes behind the scenes, to try to get this story into the media. So they leak videos to the New York Times, for example. And then the New York Times writes a story about it. This creates eventually what becomes a tsunami of media attention that creates more public attention and puts pressure on politicians. “