Terrorists consider America’s agriculture and food production tempting targets. They have noticed that its food supply is among the most vulnerable and least protected of all potential targets of attack. When American and allied forces overran al Qaeda sanctuaries in the caves of eastern Afghanistan in 2002, among the thousands of documents they discovered were U.S. agricultural documents and al Qaeda training manuals targeting agriculture.
I wish they had substantiated this even a bit, but it's still fascinating that Al Qaeda has been eyeing agriculture.