Heard about what before 1960?
How much easier it is to detect radar beams than radio ones in the galaxy?
I doubt that before 1960.
Are you merely complaining that you think this is just another statistic,
another estimate about life in the Universe?
Well, this one has some real events and numbers behind it. As for finding
actual ETI, that's why we need to keep doing SETI and perhaps start
thinking even more outside the box, like looking in the really cool regions
of the Milky Way for sources that only show up in the infrared, or maybe
we are too deep inside the issue to real the forest through the trees....