Random thoughts: Aliens

     I was recently listening to an episode of "Skeptics Guide to the Universe" and the topic of aliens came up. I believe it was concerning a way to hide the signature of Earth from aliens that would be using the same methods we currently do to find extra solar planets. And they went on to discuss the need to do so. According to Stephen Hawking, we should at all costs avoid making contact with any extraterrestrial civilization, as it would most likely spell doom for the human race.
     I disagree with Dr. Hawking on this whole heartedly, not that I think that I'm smarter than him but, logically it doesn't seem likely it would be a bad thing. The way I see it, a civilization capable of making the journey between stars, and also having the resources to take over a planet from a species that is capable of resisting could just as easily harvest whatever raw resources  they needed from asteroids or uninhabited planets.  It would make no sense to try to get those things from Earth when they are available with much less effort and in greater quantities elsewhere. The only real reason an extraterrestrial civilization would come to Earth, that makes sense, is to explore and make peaceful contact with another civilization.