Building fences to keep bad guys out?

So I came across this BBC story about vigilante sorts building their own mean-looking fence along the U.S.-Mexico border, trying to keep out immigrants and terrorists and what-not, I guess. They insist this is not xenophobia, so maybe they just don't like funny foreign people. Yikes.

This reminds me of a favorite Weekly Radio Address podcast from December 10, 2005. Go check it out for yourself, it's a riot.