For people like Polar Bum, or any who are reasonable people but are overly suspicious of "unnamed sources", your entire national intelligence apparatus operates on the basis of intelligence gathered with secret sources and methods. The entirety of our ability to have journalists get access to the truth, depends heavily on being able to keep such identities secret. They are not "finding" the truth hidden in the dirt, they are literally getting people who have the information, to share it. And often the only way to even have a chance of doing that, is to keep their identify secret.
It is a rule in the truth-finding profession that lay-people may not be familiar with. Your ability to uncover the truth is greatly diminished if you must reveal sources and methods.
Not only for because people will be able to attack those sources and force recanting, etc., but because for people at risk who see that you do NOT hold their identify secret. They will simply never come forward in the first place. And, the greater good/truth is never served best in that case.
That's ideal.
But everyone should remember *why* they are able to source original reporting, it's not entirely because they themselves will face repercussions for getting it wrong...although that's a big part of it. It's also their reputation for keeping those sources secret, and being able to withstand literally the U.S. government/president trying to breach those sources. You definitely want a reputable journalistic outlet if you have highly valuable information that you must remain anonymous on. Even then, it's still a risk.