Anonymous sources...this seems to be the week for hasing out the details that inevitably concern these unidentified individuals. Then again, it's always good to have a clear view of what to do about wanting to use a source who wishes to remain unknown. As evidenced by the box on page 225, the reporter Nathanial Carter gave his first report in 1822 and used an unidentified source while covering a story in Washington. He was most likely the first reporter to cover an actual news story and use an un-named source. We may use sources without names today often enough, but many newspapers have particular guidlenes nowadays.
"Sources who are permitted to withold their names can gripe and snipe with impunity." - This is a major deterrant for using unidentified sources, I think. If someone can say anything that they want without ever getting in trouble for it, then it's basically a free liscense to shout names at others and never get called on it by Mommy or Daddy. However, several unknown sources have helped to uncover numerous wrongdoings, like the Watergate scandal. So sources without names do have a place in journalism, but it would be wise to err on the side of caution and use them as sparringly as possible.