At the risk of compounding the senior generation's reputation for old fogeyness, here's a warning about the latest virus of so-called social networking that is infecting American journalism.

The august Library of Congress has decided to spend untold millions on archiving Twitter, that latest open exercise in getting off your chest in print anything that crosses your mind, in 140 characters or less.

Announcement of the scheme came the other day in San Francisco in a speech by Twitter's CEO, Evan Williams, in what was oh-so-cutely called its Chirp Conference. The Library itself sent out a tweet that read in part: "Library acquires ENTIRE Twitter archive. ALL tweets." It frugally used only 89 characters of the allowed 140.

Twitter, according to Williams, chirps that it transmits more than 50 million such mini-messages a day from more than 105 million registered users. Personal messages won't be archived, according to the Library, which will focus on tweets that have "scholarly and research implications."

The tweet, which seems too often to be an unedited burp from the mouth of a diner overfed with trivia, strikes me as a poor cousin of the blog, that unlimited and too often also unedited vomiting of opinion, diatribe, rumor or just plain bigotry and hate.

The magazine Wired quoted one Matt Raymond, identified as the Library of Congress' blogger, saying: "I'm no Ph.D., but it boggles my mind to think what we might be able to learn about ourselves and the world around us from this wealth of data." One also can only wonder, however, what we might be able to learn from more fully expressed ideas, particularly when submitted to responsible, professional editing.

As simple social networking, the twitter phenomenon may be as amusing and as harmless as chatter over your back fence. But when it is received and treated as a serious part of the national information flow not subject to standards of truth, accuracy and fairness, it can indeed become a poisonous virus.

News of the Library of Congress' latest flight into optimism came on the same day the White House protested a http://CBSNews.com posting of a blog by a former Bush administration aide. It alluded to Solicitor General Elena Kagan, mentioned as a possible Supreme Court appointee, as potentially "the first openly gay justice."

The posting was subsequently deleted and the blogger said he had merely been repeating a rumor. The editor of the http://CBSNews.com reported later that on checking "we determined it was nothing but pure and irresponsible speculation on the blogger's part."

The Washington Post, chronicling the protest, cited an unidentified administration official saying Kagan was not a lesbian. The Post also noted that in 2006 it had hired the blogger for its own Web site but he had resigned three days later in the face of plagiarism allegations.

If all this were only back-fence gossip, it would be one thing. It's another matter when, whether in a tweet or a Web log, it enters into the bloodstream of journalism in the guise of factual reporting or responsible opinion and analysis, not subject to any vetting or editing process.

What is the difference between a blog and writing an opinion newspaper column like this one, anyway? They both often express the writer's personal opinion on an issue or an individual of current news interest. In my case, the column is regularly reviewed by a professional editor at the syndicate that distributes it before release, subject to the editor's satisfaction on veracity.

Many bloggers at major news organizations or websites are similarly vetted but not all, and many are afforded a much looser leash, as are many of their electronic counterparts on radio and cable television. When rumor, prospective slander, libel or just plain inaccuracy get through, the credibility of all journalism suffers.

No lament from an old print practitioner is going to slay the tweeting and the blogging. But an occasional alert to the reader of the erosive quality of careless, sloppy, distorted or even dishonest writing seems warranted if the expanding fraternity of news-deliverers is to retain its long-earned reputation for truth-in-packaging.