On Wednesday, 31 August 2016 18:11:53 UTC+2, Davoud wrote:

Purely personal: I think the entire SETI scheme is a load of nonsense.
Evidence is ET is probably not out there. If ET is, we probably won't
find him. If we find him it will most likely be by accident. And
finding him would lead to 1) conspiracy theories on what the government
isn't telling us 2) speculation as to whether he is Christian 3) a
trillion-dollar preliminary study on how to make war on him 4) great
frustration as we realize we will never meet him or even talk to him.

A pessimistic but probably reasonable argument.
Interstellar travel assumes the ability to manipulate time.
Our own planet could be peopled by an entirely invisible, advanced race.
Their use of vast amounts of energy would be impossible for us to directly source.
How's that for casting blame for AGW on the [presumed] innocent?
Not to mention introducing another droplet of ultra-pure, toxic paranoia.
For the conspiracy theorists to lather into their itchy scalps! ;-)

Now all we need is somebody to explain the mild steel, featureless, cheese wedges flying lowly and slowly over people's homes! 8(