When a Story Goes Terribly Wrong  
How Newsweek botched its report on prisoner abuse—and helped set off an anti-U.S. firestorm
...Newsweek was also playing with fire by relying on a single, anonymous source to support such a provocative claim. In this case, the source was presuming to describe a still unpublished report that neither the Newsweek correspondent nor the source possessed. "You're trying to predict what's going to be in a document that hasn't yet been written," says Nicholas Lemann, dean of the Graduate School of Journalism at Columbia University. "If you have one source who says, 'I'm sitting in an office right now looking at the report,' and then they read you the page, then I'd say, 'Can you fax it to me?' Under those conditions I'd be willing to go with one source."