My personal belief is that we haven't run into them yet because they are quietly observing us from the asteroid belt. It's only been a few years since we have

My personal belief is that we haven't run into them yet because they are quietly observing us from the asteroid belt. It's only been a few years since we have been able to even begin to survey the solar system and that would mean that a bracewell probe could have been burrowed in an asteroid for millenia observing the development of the human race. Perhaps it choses to not make contact with us because we have not yet crossed a threshold that it is programmed to observe before making contact/annihilating us.