Art, I think I have to disagree that that there aren't any rational AIs out there or we'd have heard about them. We have no idea what the different governments and scientists are doing behind closed doors. All we know is what the media feeds us. There may (or may not be, I admit) one "out there". But that's not to say there is. And that doesn't mean there isn't, either.
A good example of this is when I was a kid, I remember reading UFO magazines (there were lots of them when I was younger) and seeing people's pictures in the magazines of UFOs that looked like black darts or triangles. A few years or so later, these SAME triangular aircraft started showing up in more mainstream magazines as a government stealth jet. I forgot the name of the plane but others probably could find it. It was being tested and created a long time in secret, probably even before those who photographed it as UFOs even knew it existed.
The Flying Saucers I think we won't see or for a long while yet because the shape doesn't really lend itself too well to air/space travel. I think they either are still working on it or they gave up. Then again, I don't keep up with the UFO community so I don't know what people are still seeing (and if they are really seeing it or if they are just imagining it - another thing to consider).
The black triangular jet though was a good example of government work that was being witheld from the public until they were ready or willing to disclose it.
So who's to say we don't already have such an AI in existance? Who's to say it already isn't aware of our society or even somehow participating in it in some way?
With the way we all have learned to take computers for granted (they do all kinds of things, such as mail out letters, analyse applications, etc. etc.) They affect or touch nearly every aspect of our lives. We have no idea if one of them is a government or scientific experiment AI (or even one in the private sector) that is being used for some form of public processing or function or if it's just another computer doing a task? Maybe it is doing this for us and then consulting in a meeting with those that need the data. Who knows?
Then again, maybe it hasn't even happened (yet). But, we won't really know for sure until we are told it has happened. Or have other concrete evidence.
For now, I would like to think that there is one in existance - at least one. After all these years of research. Usually what we see in the public format is something much less than what governments and scientists can already achieve. So if we are at a point where we can hold some kind of conversation at all with our own home computers, who knows what a secret computer run by government or scientists can do?
We won't know, as I said, until someone tells us or shows us...
