1 Martian 1: Okay. We need to conduct Earth operations more carefully from now on.
2 Martian 1: We'll restrict ourselves to recon flights, mutilating cattle, and abducting people with no credibility for embarrassing probing experiments.
3 Martian 2: What about the psychics who will correctly divine our existence?
4 Martian 1: We'll feed them some rubbish about wanting to bring peace and universal harmony. Nobody will believe that.

This could be played two different ways by the Martians.

A. The option of choice is to present a message of peace and universal harmony, in the knowledge that nobody in their right mind would believe such a thing, thus discrediting the only people who really have a direct insight into their existence - the psychics.

B. Present a message of peace and universal harmony, but shoot to kill.

(Honestly, I'm not trying to mention every single damn page in TV Tropes. It's just that when I do a tiny bit of research to find something to say in these annotations, they inevitably pop up. Quit writing so darn much interesting stuff about pop culture, guys!!)