According to David Cohen at the U.S. Treasury Department, terrorist organizations have accumulated over $120 million through kidnapping for ransom (KFR) between 2004 and 2012—a fairly enticing supply of cash for organizations that have increasingly turned to criminal networks and techniques to finance attacks.

http://www.krmagazine.com/2013/07/05/kidnapping-for-ransom-too-lucrative-for-terrorists/