In reality, I dislike using unnamed sources for the very reason I'm writing about them today: they cannot be checked for veracity, and that makes them suspect. In fact, whenever a quote or statistic is provided by an unnamed source, your skeptic's flag should start blowing in the breeze. The best way to use a legitimate unnamed source is to back it up with a named source--someone who is willing to reveal his or her identity and serves in effect to corroborate the source that isn't.
Of course, that's not always possible, especially when dealing with secretive political, corporate, military, or economic issues. In such instances, unnamed sources are not only advisable, they're absolutely necessary. Without them, we would have no whistle blowers and watchdogs. Without whistle blowers and watchdogs, we would have no democratic society.
Unfortunately, a growing number of news outlets are using unnamed sources recklessly--and, often, fraudulently. If you falsely claim to have an unnamed source that revealed potentially damaging or embarrassing information to you, you will eventually be discovered and disgraced. You will probably also be fired, unless you're working for yourself, of course, in which event you should consider getting into an entirely different line of work immediately.
Unnamed sources are also a potential embarrassment for the news outlets that rely upon them for another reason. Reporters who are allowed to get away with using unnamed sources are often too lazy or unprincipled to work around them. When I see an unnamed source as the only source of information in a news piece, I discount the veracity of the piece, period. If the reporter backs that unnamed source up with one or more named sources, or even with his own diligent investigative legwork, I'm more likely to be open to the real possibility of all of his sources.
So, the next time you see, read, or hear a story about someone that relies solely upon the information garnered from an unnamed source (or worse, several of them), think twice before believing it. Otherwise, the only real victim is you!