The simple reason BuzzFeed should not have published the Trump Russia dossier
The journalistic principle at stake here is very simple: You do not publish damaging, unsubstantiated, anonymous allegations.
You don't do this even if the subject of the allegations is extremely prominent; even if the allegations are being widely gossiped about; or even if the subject is a loathsome person with a long history of spreading damaging, unsubstantiated rumors about others.
And saying "some guy said this to me, I don't know whether it's true but here you go" does not absolve a journalist of either legal or ethical obligations for accuracy.
BuzzFeed acknowledged that they do not know whether the claims in the dossier they published are true. They say they published it because it "has been circulating among elected officials, intelligence agents, and journalists for weeks," and they felt that it should be published "so that Americans can make up their own minds about allegations about the president-elect."
Alternatively, they could have put it this way: Many people are saying something very serious, very serious about what Donald Trump was up to at the Ritz Carlton in Moscow. We're not saying the allegations are true, but we heard about them from an "extremely credible source," and we'd better get them out there so everyone can figure out exactly what's going on.
Amazingly, BuzzFeed failed to run down some of the allegations in the dossier that could be assessed relatively easily - for example, Trump's lawyer Michael Cohen has argued fairly convincingly that he did not visit Prague in August or September, as the dossier claims.
To the extent the dossier is being discussed within the government and that fact is newsworthy, you can do what CNN responsibly did - report on the existence of the dossier without publishing the unverified claims it contains.
Just because Donald Trump is going to be president is not an excuse to behave like Donald Trump.
Since Trump rose to prominence by spreading the outlandish lie that Barack Obama faked his birth certificate, and steamrolled his way through the primary by spreading rumors like that Ted Cruz's father may have been somehow involved in the assassination of John F. Kennedy, there is admittedly a certain justice in him become the subject of irresponsible rumors.
But the job of the press is not to dole out justice. It is to deal in facts, treat subjects fairly, and make readers smarter. On those counts, BuzzFeed failed.