The Fermi Paradox asks, "Where is everybody?" Could intelligent life be mostly self extinguishing?

This will be the last of the Strange Universe Series—2011 questions.

Conservative columnist and Fox News commentator Charles Krauthammer wrote an unusually thoughtful piece in today’s Washington Post on this question. Please read his musings here then weigh in. So, Where is everybody? Why isn’t the Universe with its vast, near infinite number of stars filled with radio waves from alien cultures. What explains the strange silence?

Here are the previous Strange Universe Series—2011 questions.
1—How do you envision space in more than 3 dimensions, then rotate it to see what happens?
2—How can we be certain the Uncertainty Principle is certain?
3—If the universe is infinite, how big is what it is expanding into?
4—In an expanding universe, how do separate galaxies manage to collide?
5—Since space is expanding and is linked to time, isn’t time expanding as well?
6 —How can space expand between individual hydrogen atoms?
7—True or False? When you’ve seen one entropy, you’ve seen them all?
8—What’s the matter with matter?

The entire 20 Questions Strange Universe Series—2010 can be found here.