American troops first discovered Arab combat videos in Iraq and Afghanistan. These are made by taking video images of terrorist attacks on American troops, and adding a music or spoken word audio track. In some cases, the audio was Arab rock and roll, the kind of music that would get wannabe jihadis ("holy warriors") all fired up. U.S. troops had their own video cameras, and were collecting a lot of combat videos. So, copying the enemy practice, they added music scores (usually heavy metal or rap) to the videos and began passing them around.
Some of these videos, without the sound track (a copyright violation, since the audio is almost always used without obtaining permission from the bands), have shown up in the StrategyPage Gallery. The troops will probably continue to make, and distribute, these videos, but without the usual screens identifying the unit involved, or images that make it possible to easily identify who the troops are. The troops are not terribly concerned about Arab morale, after a tour in Iraq.
The U.S. Department of Defense has forbidden American troops from making music videos from their combat videos, and passing them around. This is so that Arab feelings won't be hurt. These videos show Islamic terrorists getting killed, and Arab media depict this as a sign of American barbarism and anti-Arab attitudes.