[Bartweiss]

As Greenwald pointed out years ago, it's sensible for readers to ask why sources are anonymous.

If they're saying something inconvenient to their government or employer, that's neutral or even positive for their credibility. If they're saying something convenient but classified or otherwise not-for-release, that's generally neutral; 'authorized leaking' is an established practice. But if they're saying something that won't cause them problems and isn't a secret, then it's strange. It raises the possibility that they're anonymous because the claim isn't true and they don't want to be embarrassed, or even that the story writer encouraged anonymity to hide the weakness of the source.

If Bloomberg is saying "we used 17 sources including intelligence officials and an anonymous source who confirmed the hack", well, easy money says the key anonymous source doesn't measure up to the other 16.