The weather here in Washington this week was hot and humid. That's on background, of course. Do not quote me. You can use the information only if you attribute to "a beltway source who could not be named because he is not authorised to speak about meteorology".

Here's what you can quote me on: such ridiculous, pusillanimous, deceitful attributions are a standard tool of the Washington press corps, which as a group is too caught up in its own self-importance and petty competition to understand it has become the cabin boy of the political class. In the name of supposedly informing the audience, Washington reporters are co-conspirators in an ongoing fraud. Here's what it looks like:

USA Today: "Mitt Romney is planning a bus tour ahead of the Republican national convention. A Romney campaign aide confirmed the bus trip to USA Today. The aide, who is not authorised to discuss the trip publicly, asked for anonymity because details have not yet been announced."

Oh, wait. They have too been announced. Just now. By the Romney campaign.

These are not whistleblowers being protected, or even insiders going out on a limb. The epidemic of blind quotes [when interviewees don't want to say anything on the record] is a standard way of giving a platform to officials speaking in an official capacity, yet with zero accountability. The practice is also supremely manipulative, giving the most banal information the allure of forbidden fruit.

At its worst, the game can allow the vice president of the United States to leak phony intelligence to the New York Times and later refer back to the leak as independent journalistic confirmation, leading to invasion and hundreds of thousands of deaths and a trillion dollars in squandered treasure.

On the plus side, the Times scooped everyone.

The Iraq disgrace aside, obscuring official sources might be understandable if this journalistic worst practice were in the service of earth-shaking news. It almost never is. Here are some blind quotes from just the last few days:

The Atlantic: "A former McCain staffer who saw the summary of Romney's tax data independently confirmed former Republican presidential nominee John McCain's account that there was nothing disqualifying in it, but said he was not authorised to provide more detail from the confidential report." Associated Press: "The Democratic official would not comment on the exact language of the pro-gay marriage plank approved by the drafting committee. It was unclear if the party would call for any national action to legalise gay marriage . The official spoke on the condition of anonymity because they were not authorised to speak publicly about the platform committee's decision." Reuters: "Members of the Federal Trade Commission voted to approve a consent decree that will allow Google to settle the agency's investigation but admit no liability, said one of the sources, who was not authorised to speak on the record."

And here's the thing about epidemics: they spread. In recent days, anonymity was provided to sources in stories about investments, the courts, an NBA player trade, a shopping-centre sale in Sacramento, California and at least one huge development of historic significance: concern over Jimmy Fallon hosting the Oscars:

LA Times: "ABC has raised objections to having the late-night star from rival NBC play emcee on its Oscar broadcast, these people said, but the network has no authority to veto the choice of host. The show is put on by the Motion Picture Academy, and Tom Sherak initiated the discussions before his term as academy president ended on Tuesday, according to the people who were not authorised to speak publicly."

Congratulations, stewards of freedom, you have heroically served the public's right to know.

The blind quotes, though, are not even the worst of it. The New York Times recently revealed that reporters are not merely working on background, they negotiate after interviews what comments may be used and send them to sources for prepublication approval. The sources routinely edit those quotes before turning them back over to news organisations.

As media ethicist Edward Wasserman so aptly put it, "At this point you're no longer talking about an interview; you're talking about a press release … And what happens is Washington becomes no different from Beijing, in terms of reporting what authorities want reported".

Once again, this turns out not to be some sort of rare practice confined to sleazy blogs. It is a sleazy practice embraced by the most venerable journalism institutions, desperate to feed on the scraps offered by official Washington, no matter how degrading and unscrupulous the transaction. One Washington Post reporter was caught sharing an entire draft of a story about Texas learning standards with university of Texas officials.

The backlash was swift. Embarrassed by the revelation, the Post issued updated policies on quote approval and draft-sharing, absolutely forbidding the practices. Absolutely and unequivocally. Except when the reporter and editor agree it's OK.

"We should not allow sources to change what was said in an original interview," said executive editor Marcus Brauchili in a memo, "although accuracy or the risk of losing an on-the-record quote from a crucial source may sometimes require it. A better and more acceptable alternative is to permit a source to add to a quotation and then explain that sequence to readers."

You tell 'em, Marcus. Take no prisoners.

Meanwhile, the National Journal and Bloomberg news followed the McClatchey Newspapers Washington bureau in instituting a real ban on quote sharing, as articulated by McClatchey bureau chief Jim Asher: "I make this commitment to our readers, and to our citizens: McClatchy journalists will report fairly and independently. We will not make deals with those in power, regardless of party or philosophy."

Yes, they got scooped on the Romney bus blockbuster. All they have now is their independence. And their dignity.