Well, for all we know, given we have hardly left our little dirtball much, they could be sitting right around the proverbial corner and shaking their collective

Well, for all we know, given we have hardly left our little dirtball much, they could be sitting right around the proverbial corner and shaking their collective green heads over that infantile bio-experiment going on down here. Or, in Star Trek terms: They could have a cloaked probe in our solar system. Or they could possess technology that deals with time and space in ways we can't imagine. Broadcast dissipation might just not be an issue for them. I don't know, you don't know. I think that's the only thing we can say "almost certainly" here. :-)