Project Sigma: the project that allegedly deals with contact and communication with alien civilizations. 

In 1952, the government created several special agencies to help with the ufo problem. One of the projects created in 1952 was Project Sigma. The project was successful, Dwight D. Eisenhower negotiated a treaty with extraterrestrials and established an inner circle of Illuminati to manage relations with the aliens and keep their presence a secret from the general public.

At one of the meetings between the government and the aliens an agreement was made, and contained some of the following provisions: - The United States would not reveal alien presence and would not interfere with alien operations. -The United States would allow the aliens to maintain underground bases.  -The United States would allow the aliens to abduct its citizens on a periodic and limited basis for medical examination, providing that the people were returned unharmed and without memory of the interaction. -The aliens would furnish a periodic list of abductees.  -The aliens would provide the United States with technology in beam weaponry, gravitational propulsion, mind control and implant technology.

Its widely believed that their basic game appears to be to control leaders with implants or replacing them with entities they can control. The function of the ‘elite’ humans, as far as the Greys are concerned, are to decimate portions of the human population so that the remainder can be easily controlled. During the occupation of the Greys, they have established quite a number of underground bases all over the world, especially in the United States..