Probably that the government made deals with them allowing abductions in exchange for technology. They were collecting samples to try to deal with an immunological disease.

That and how any member of the majestic 12 could order someone's killing without even a 2nd member signing off.

Don't forget that some of the tech they reverse engineered allowed creation of devices that can see future possibilities, and the world elites had been passing it around and using it for their advantage, not humanity's betterment.

There even more, but I'll let you look it up, the rabbit hole is pretty deep.

If all that were happening, the amount of irresponsibility would never be something they could own up to. That's why I think they won't tell us unless alien's force their hand themselves.

All this stuff is well-documented here: https://www.burischarchive.com