[link|http://www.eweek.com/article/0,3658,s%253D701%2526a%253D26875,00.asp|I can believe that]
Excerpt:
A senior Microsoft Corp. executive told a federal court last week that sharing information with competitors could damage national security and even threaten the U.S. war effort in Afghanistan. He later acknowledged that some Microsoft code was so flawed it could not be safely disclosed.