If we heard that the ACLU openly defiled our Holy Bible, we wouldn't react to favorably now, would we?
Regardless of what we think about Islam, it is absolutely vital that we respect the Islamic faith (or non-faith). The quickest way to turn the entire Islamic world against us, including Iraq, Afghantistan, and the student movement in Iran, is to disrespect Islam. We can't afford to be shooting the same people who were cheering us on earlier.
Even if this is a Kabul "rent a mob" with elements of Taliban and Al-Qaeda thrown in, we should treat this with utmost respect and caution. How the Afghan government and our troops react will determine our image in the Islamic world.
Marilyn Manson regularly tore pages out of the bible at his concerts. How many people were killed in the "ensuing" riots?