http://www.csmonitor.com/2005/1017/p02s02-usfp.html?s=hns
Peter Grier
"Some experts suspect that the letter is a fake, and that the CIA - not Al Qaeda bigwig Ayman al-Zawahiri - may be its true author. It was US Intelligence that made public the 13-page missive, after all. Others call it a fascinating document, and say much of it rings true."