As Daily Kos perceives it
Currently there is a diary near the top of the recent diary list that attacks Hillary Clinton for a supposed bigoted comment. The sources the diarist cites are not credible, to say the least, and are more correctly described as right wing websites.
I will not link to this diary as 1) I expect it to be deleted by diarist soon, and 2) I will not spread such filth any further.
But this does raise an opportunity to discuss the First Rule of the Primary Wars. It is expected that there will be diaries criticial of any and all candidates during this time. No one can complain about that. Indeed, your candidate will not be our nominee unless he or she can survive our scruntiny. But, when writing such diaries critical of a candidate, you may not now or ever use source material that emanates from the right wing or Republicans to support your criticisms or attacks.
If your source is NewsMax, delete the diary.
If your source is Insight, delete the diary.
If your source is Drudge, delete the diary.
If your source is Free Republic, consider suicide.
Daily Kos will not be used as a Right Wing echo chamber, for they already have enough echo chambers of their own.
There's an easy way for Kos diarists to get around the mandate - what's on those four sites is bound to be elsewhere. All Free Report stories originate elsewhere, as do virtually all of Drudge's and most of NewsMax's.
And, as this commenter notes, no mention of LGF. A Kos commenter notes that Instapundit and Redstates were also left off the enemies list. They get their material from other sources, too. Unless Markos Zuniga invents a computer virus that allows him to monitor the surfing habits of his diarists, they're free to get material from the "right wing echo chamber" all they want, as long as they cite the echo chamber's news sources (other than Insight).
Of course, left-wing echo chamber material is fair game.