Yes, thanks for explaining the origins, harrisj--it is certainly useful! You may not be aware, though, there are a whole lotta* wordie-denizens who do not live in the United States, so it isn't necessarily that readers of the site would be Martians. You'll also find a whole lotta* lists and words that don't make much sense to Americans.
:) Welcome to Wordie!
*I want kudos for resisting using a new term I just learned for "a whole lot of": asston.
P.S. Pro, and others, this phrase was made comical by Stephen Colbert of the Colbert Report, among others. You can see clips of his show at Comedy Central (dot com)—I think. And there are quite a few Colbert Report lists around here. (I have one but haven't kept up with it.)
For those readers from Mars who wonder about the origins of this, this phrase is of course the perfectly sarcastic retort to George W. Bush's explanation of 9/11, and the with-us-or-against-us mentality in the years that followed. Rather than explore the complex origins of terrorism against the US, he summarized their motivations as being solely that "they hate our freedoms."