Contrary to their name, anonymous sources are not actually “anonymous.” These are not unknown people hiding behind hotmail accounts and hidden phone numbers. They are instead confidential sources, known to the journalist reporting the story. When a story says a source is anonymous, it does not mean unknown. The person is vetted and is a legitimate source on the story who wishes to remain un-named. The journalist and his immediate supervisor are aware of the source’s name, position and expertise, they just are not able to use that information in the story.
Anonymous sources also are not necessarily low level people. The world’s most famous anonymous source ever, Mark Felt — known for years simply as “Deep Throat” — was the Associate Director of the FBI, a high-ranking government official who gave the press the information they needed in exchange for anonymity.
Confidential sources are important to investigative journalism and are sometimes necessary to confirm information, but they are never unknown people living underground and tipping off reporters. They are people that journalists know in person, identify in other stories, interview on a regular basis, and on occasion have a drink or two at the local dive bar with.