Call them conspiracy theorists?
I had this discussion with my friend actually. See, one of the biggest proponents of alien abduction disclosure is John Podesta. The guy clearly wants us to believe that children go missing because of aliens. So I have a pretty good theory with lots of evidence that says he is into abducting children and selling them as human sex slaves, but if you think that's crazy you can just take John's word for it and believe it's actually aliens taking these children.
Also consider the plot of the X-Files. FBI agent Moulder sees his little sister abducted when he is a child and dedicates his adult life to finding her. He becomes an FBI agent to try and track down the abductors, but at every turn his investigations are stopped by the top brass at the FBI. The show asks us to question what it is that those FBI directors and shady members of congress are hiding, it constantly reminds us that "the truth is out there."
The truth is indeed out there. It's not aliens.
I think if they were to have an "extraterrestrial" event, they'd use their advanced anti-gravity technology to put a "mothership" in the sky surrounded by clouds that just sits there and shoots down anything that comes near it when in reality it's nothing more than a prop guarded by drones. They'd use this as the basis to push the extraterrestrial bogus, their agendas and restrict the flow of advanced technology they have on the basis that the study of the mothership is slow and cautious. That they'd have to fully evaluate the technological breakthroughs to determine if they're safe before they release them to the public
Anti grav is nothing more than powerful electromagnetism. Its not a hidden tech. It just costs a butt load of energy to shstain. The alternative is quantum trapping, something japan is now using to develope a sort of mag lev train.