“You asked me earlier why The Domain, and other space civilizations do not land on Earth or make their presence known. Land on Earth? Do you think we are crazy or want to be crazy? It takes a very brave IS-BE to come down through the atmosphere and land on Earth, because this is a prison planet, with a very uncontrolled, psychotic population. And, no IS-BE is entirely proof against the risk of entrapment, as with the members of The Domain Expeditionary Force who were captured in the Himalayas 8,200 years ago.
No one knows what IS-BEs on Earth are going to do. We are not scheduled to invest the resources of The Domain to take total control of all the space surrounding the area at this time. This will occur in the not-too-distant future — about 5,000 Earth years — according to the time schedule of The Domain.”
– Excerpted from the Top Secret transcripts in the book Alien Interview