Neal Krawetz... gave an interesting presentation today at the BlackHat security conference in Las Vegas about analyzing digital photographs and video images for alterations and enhancements.

Interesting were the examples Krawetz gave of al Qaeda images. Krawetz took an image from a 2006 al Qaeda video of Ayman al-Zawahiri (above right), a senior member of the terrorist organization... After conducting his error analysis Krawetz was able to determine that al-Zawahiri's image was superimposed in front of the background -- and was most likely videotaped in front of a black sheet.

Wish I hadn't missed that one. I wonder if he is re-presenting at defcon...