Jacques Vallee writing in "The Invisible College" on extraterrestrial contacts:

It is true, in my opinion, that Geller and other silent contactees can produce phenomena that are inadequately explained in conventional terms. It is also undeniable that these phenomena do not constitute an end, but a means,  for convincing both scientists and non-scientists of the opportunity for contact with a higher source of information and power. Here lies the danger, because historically, such messages have never revealed anything that was not already known within the intellectual grasp of man….(I)t has been consistently observed that messages produced by automatic writing could tap the knowledge, conscious or unconscious, of the participants….

(Vallee relates an unpublished case and states)

Nothing that is within the power of any one of the participants is beyond the power of the alleged entity.