Anything that’s not understood becomes evidence for conspiracy.

In this week's eSkeptic, Pat Linse explores the birther's claims that President Obama's long form birth certificate is actually a forgery.  She analyzes the claims, explains how the supposed anomalies on the certificate could have come about, and even tells how she would forge a document that would be far superior and simpler than what the birthers' think was used.

Best of all is Pat's Maxim, that succinctly describes why so many conspiracy theorists can't be persuaded:

Anything that’s not understood becomes evidence for conspiracy.

That's it in a perfect nutshell.  It describes why some guy sitting in his office thinks that photos from the Moon should look different.  It's why someone on a youtube video wonders out loud why there isn't more debris at the Pentagon attack of 9-11.  It's simply because they don't understand the information, and thus declare that someone is trying to fool everyone--but they're too smart to fall for it.

See more about the Dunning-Kruger effect.