See how they run in the Post, the Timeses, and the Journal.

Ombudsmen, editors (PDF), and entire publications love to hold forth on the importance of limiting anonymous sources, yet masses of anonymice continue to nibble on the credibility of many major dailies.

In the old days, the only reliable way to trap anonymice was to read newspapers closely or subscribe to a service like Nexis. Nowadays, anybody who types a keyword like anonymous or anonymity into a news tracker like Google's can capture the little beasties for examination. Slate intern Kara Hadge and I commenced such an expedition two weeks ago, instructing Google to e-mail us links to all news stories containing either word in the New York Times, the Washington Post, and the Los Angeles Times. Factiva culled the Wall Street Journal for such stories. We left USA Today out of the mix because it pretty much bans anonymice.

Obviously, this crude filter didn't yield every anonymously sourced article in the newspapers surveyed because many stories slip in anonymously sourced information without using the A-word. Some newspapers attribute anonymous information to "a source" or to "knowledgeable sources." To snare every unsourced morsel in the top dailies would require a mob of graduate students working 18 hours a day, such as the crew that labored for New York Times Public Editor Clark Hoyt recently. As an army of two, Hadge and I stalked only the easy prey.

(Additional notes on methodology: We collected only the first anonymous passage in stories that contained more than one. We excluded wire stories, opinion pieces, Web news and blog stories, and all stories without bylines except for those where the byline was withheld to protect a reporter filing from a dangerous location where he might suffer direct retaliation for his published work or for being physically present, such as Zimbabwe, Burma, and Darfur.)

We dumped our catch into a Google spreadsheet, which we've embedded into this page. It notes the name of the newspaper, headline, URL, byline(s), and date, plus an assessment of who really benefited from the anonymous sourcing—source, reporter, reader? (Alas, the spreadsheet's sorting function is crippled, but you can still drag the data into your own spreadsheet and sort there.)

To view the whole Google spreadsheet, see this page.To open the news stories on the embedded page, right-click on the link and chose "open in new window."

While radically opposed to anonymous sources, I'm not an absolutist about it. Often a journalist has no alternative to attributing his information to an anonymouse when reporting, say, a criminal investigation or from a war zone. Likewise, many national-security stories cannot be reported without citing unnamed sources. The NSA story, the CIA prison story, and the torture story could not have been undertaken without anonymous sources.

The very best national-security reporters operate under what I call the Dana Priest rules: They're disciplined about their use of anonymous sources, and give more credence to whistleblowers than blowhards. They present multiple sources, increasing the likelihood that the information is accurate. They serve their readers, not their sources' agendas. And the information they publish is remarkably specific—proving dates, locations, events, circumstances, participants, quantities, and the like—which makes it falsifiable. By falsifiable I mean that the very specificity of the anonymously sourced information opens the article to the possibility of being proven wrong by naysayers.

Compare the work of Priest-rules-compliant reporters with that of the less scrupulous, who lard their stories with quotations from anonymice speaking the sort of rubbish that would never make it into the newspaper if the info had been given on the record. Take, for example, this recent Los Angeles Times story that attributed to a "Democratic strategist" the utterance that there is "a lot to recommend" Evan Bayh as a prospective vice-presidential nominee! Boy, that's really hot news.

Some reporters smuggle anonymous quotations into their stories as payment to sources for taking the time to talk to them, even if the sources said nothing of substance. Some reporters use anonymous sources to state the obvious (see the Evan Bayh example above) because their editors won't let them say it on their own authority. Other reporters have been trained that any quotation, no matter how vacuous, will increase the truth value of a story. So, they plug them in. Then there are the diabolic journalists who publish anonymous material solely because it creates the mystery and tension their article inherently lacks. And some reporters are just loose. (For an informative, inside discussion on the proper use of anonymous sources see this chat between readers and New York Times Managing Editor Jill Abramson from June 2008.)