Target: Vatican

The FOXNews article mentions previous threats by Islamist against the Vatican:
FOXNews.com
Is the Vatican a Target for Terrorists?

Here's another from a few years back claiming the terrorists called off an attack on the Vatican right before the 9/11 attacks:
The Advertiser:Al-Qaeda's Vatican attack:paper (archived)

Let's come to an understanding with Islam; 'we won't target your non-military holy sites if you don't target ours, the minute you do then one of the pillars of your faith will be unavailable to you for generations. ' We CAN do it; the only question being WILL we do it.

(right here I am resisting the urge to insert Dirty Harry picture 'go ahead punk, make my day' )

Place idea in head, cover with rag and heat at 120 degrees for a generation.