The panic they could cause would almost be enough. So, using Occam's Razor as a gauge, why haven't they done this yet if they have them? Somewhere - anywhere? Talk about getting leverage.
FWIW, this information has been around much longer than this recent WMD article. Even the Clinton administration believed it was possible... a book by the name "The Age of Sacred Terror," discussed many of the same things that Williams first presented in Osama's Revenge (released last yr). That book was made up of almost entirely open source data, and a lot of it checked out. We even have PhD authors such as Graham Allison (of the LIBERAL Harvard University) claiming that there will be a nuclear attack on the U.S. at some point, possibly this year. People are quick to dismiss because of the source, without investigating further.