If our terrorist enemies have been successful at cultivating a false notion of expertise, they’ve done an equally convincing job of casting themselves as pious warriors of God. The Taliban and al-Qaeda rely on sympathizers who consider them devoted Muslims fighting immoral Western occupiers. But intelligence picked up by Predator drones and other battlefield cameras challenges that idea—sometimes rather graphically. One video, captured recently by the thermal-imagery technology housed in a sniper rifle, shows two Talibs in southern Afghanistan engaged in intimate relations with a donkey. Similar videos abound, including ground-surveillance footage that records a Talib fighter gratifying himself with a cow.

Pentagon officials and intelligence analysts concede privately that our foes also have a voracious appetite for pornography—hardly shocking behavior for young men, but hard to square with an image of piety. Many laptops seized from the Taliban and al-Qaeda are loaded with smut. U.S. intelligence analysts have devoted considerable time to poring over the terrorists’ favored Web sites, searching for hidden militant messages. “We have terabytes of this stuff,” said one Department of Defense al-Qaeda analyst, speaking on the condition of anonymity. “It isn’t possible that they are encrypting messages in all of this stuff. Some of these guys are just perverts.”

Tawdry though this predilection for porn may be, it is not necessarily trivial. There is, after all, potential propaganda value in this kind of jihadist behavior. Current U.S. public diplomacy centers on selling America to the Muslim world, but we should also work to undermine some of the myths built up around our enemies by highlighting their incompetence, their moral failings, and their embarrassing antics.