Not only "why hasn't he been commited?" but "why is he holding lectures at colleges such as MIT?"
It wasn't a lecture--it was a debate hosted by MIT:
http://video.google.com/videoplay?docid=-6165833039675318127&q=timecube
http://video.google.com/videoplay?docid=1943356687575601024&q=timecube
http://video.google.com/videoplay?docid=-5080004761497767389&q=timecube