Even if a civilization out there had faster-than-light travel, they would most likely not know we were here. They would need to decide to come explore near us, probably need to expensively slow down to sub-light speeds to look for signs of life near here and pick up our emissions on some old archaic piece of equipment they happened to bring along.

Would a much more advanced civilization spend their exploration budget to look over uninteresting primitives like us, or would they go off in search of other more advanced civilizations like their own?