Erik Wemple, who writes a blog on media issues at the WaPo, has this post on union organizing efforts at Huffington Post.  I was struck by this paragraph:

The document touts the merits of a progressive news outlet internalizing its principles: "Unionizing is one way for us to stand by the ideals we often preach on our site," notes the letter.

The signers of the letter are not, for the most part, opinion writers designated as such.  Their titles imply that they are in the straight news business.  Yet they see it as their job to "preach" their "ideals."

The danger is that too many people today are getting most or all their news from people who have no dedication whatever to objective reporting.  As the line between advocacy and reporting becomes ever more blurred, "facts" that are either undetermined or outright false become accepted as absolute truth by people who never hear them questioned.  Elections and the direction of our society may turn on widely believed myths with no connection to reality.