Quote Originally Posted by jamstigator
Our lack of finding signs of intelligent life via SETI and so on is a little troubling. Granted, we haven't looked very hard at all. But it occurred to me that there could be a scary reason why we aren't picking up the signals of other intelligences in the general vicinity (say, within 10,000 light years).

While I concur with your post I can see why SETI has yet to stumble upon information sent out by other forms of life with no problem. Life of any level of intellectual ability would be rare with in even our tiny , little, small uninteresting galaxy. And if some one out there was around for a hundred thousand years it could be a million more years before actually received their first broadcast when their Marconi fired up his first transmitter. And we may have received detailed information already and it got here when we were burning the scrolls at Alexandria and heading into the dark ages. Thus is the vastness of this bubble of matter and energy. Drake gave us a reasoned view of the possibilities in his formula ( The Drake Formula--Estimating Life in the Universe )
And even if the Universe is Teaming with intelligent life we may never know it before something puts our lights out for good.