One poorly reported fact is how many times mainstream media have been caught reporting from unscrupulous sources as if it were gospel. Using mainstream media as a marker for “truthiness” is no guarantee that your news source is accurate or reasonable.
Conversely, remember who broke the Bill Clinton sex scandal wide open? Hint: It wasn’t a mainstream media outlet. It was that gossip rag, The Enquirer. I can recall the horror and chagrin of the professional news media journalists where they found themselves reading the details about Bill Clinton’s behavior in a tabloid.
Unfortunately, this well intentioned effort is going to be abused. Just as the sun rises in the east, various organizations will seek to discredit and squelch news reports that don’t match their narrative. Even “widely respected” meta-news sources such as snopes.com get it wrong sometimes because they validate their facts from places that aren’t exactly free of agendas themselves.