If you've ever been closely involved in a news story -- either as a participant or a witness -- you know what it's like to turn on a newscast that night or pick up a newspaper the next day and see how it's been reported. Unfortunately, there's often something wrong.
It could be as simple as a misspelled (or mispronounced) name or an incorrect address. Or it could be a more significant error of fact, omission of detail or misplacement of emphasis. But one way or another, a reporter's second-hand version of events seldom matches the recollection or perspective of first-hand experience.
When that happens, it makes everything else you read or watch or hear on the news seem a little less credible. It causes you to question all the other stories with which you don't have any direct connection. That loss of confidence adds to the public's growing mistrust of journalists and their beleaguered profession -- pejoratively lumped together as the "mainstream media."