Yes, this really is a frightening possibility. There were lots of discussions about terrorists attack on our food/water sources just after 9-11.
Heck, our food supply is already being contaminated by rocket fuel. Take a look at the article in the link below. Iceberg lettuce from Belle Glade, FL, leaf lettuce from AZ, bottled spring water from CA and TX, organic milk from MD, all with rocket fuel in them.
http://info.mgnetwork.com/printthispage ... ap.tbo.com
/ap/breaking/MGBJUC0T62E.html&oaspagename=www.tbo.com/ap/
story.htm&image=tbologo80x60.jpg