Alien beings

I stupidly watched a very disturbing WikiLeaks video late last night of American helicopter pilots gunning down innocent civilians in Bagdad, including two children. Twelve died, including a Reuters correspondent whose camera was mistakenly identified as a weapon. The jocular tone of the pilots on the sound track sounded like young boys playing a video game. "Nice!" was heard more than once, as civilians were hit.

At dinner the other night, a journalist friend said there are three credible theories about the possibility of extra-terrestrial life.
1. It doesn't exist.
2. It exists, but doesn't wish to make contact with us.
3. It might have existed, but at a certain point in their development, all sentient beings self-destruct.