Dick is a friend and he postulated this idea in the 1960's. He and his wife Nancy wrote and published a book about it called "The Siren Stars". He also was, before retirement, a leading particle physicist at Fermilab in Batavia, Illinois. So at the time of this idea, he was about 20 years ahead of the curve and 30 years ahead of IT (although Fermilab was one of the first organizations to have the internet). 3'rd replicator entities would , by nature, operate at a much different level. Could they not gain slight entry and then analyze and improvise their way in through the portals, gaining control?