He has more recently been noted for his belief that a major war between the supporters and opponents of intelligent machines, resulting in billions of deaths, is almost inevitable before the end of the 21st century.:234 He suggests AIs may simply eliminate the human race, and humans would be powerless to stop them because of technological singularity. This prediction has attracted debate and criticism from the AI research community, and some of its more notable members, such as Kevin Warwick, Bill Joy, Ken MacLeod, Ray Kurzweil, Hans Moravec, and Roger Penrose, have voiced their opinions on whether or not this future is likely.