The Wall Street Journal, November 15, 2009 by John Yoo
http://online.wsj.com/article/SB10001424052748704431804574537370665832850.html#printMode
Prosecutors will be forced to reveal U.S. intelligence on KSM, the methods and sources for acquiring its information, and his relationships to fellow al Qaeda operatives. The information will enable al Qaeda to drop plans and personnel whose cover is blown. It will enable it to detect our means of intelligence-gathering, and to push forward into areas we know nothing about.