WASHINGTON - These days, CBS News anchor Dan Rather and his colleagues at the network's magazine program 60 Minutes IIare enduring an unusual wave of second-guessing by some of the public and fellow journalists.

For that, they can thank "Buckhead."

It was a late-night blog posting by this mystery Netizen that first questioned the validity of documents Rather cited Wednesday as proof that George W. Bush did not fulfill his National Guard duty more than 30 years ago.

Buckhead refuses to further identify himself, other than dropping hints that he is a male who lives on the East Coast - preferring to proclaim that the scramble to verify the contentions in his posting marks an extraordinary achievement for a medium that has operated more as an underground world of ideological venting than a source of legitimate news.

But Buckhead is vehement about one thing: He acted alone when he posted, to the conservative Web site FreeRepublic.com, what was widely believed to be the first allegation that the CBS report relied on documents that could have been forged.

"Absolutely, positively, on my own, sitting at my computer in my bedroom just before midnight - but not in my pajamas," he wrote in an e-mail exchange with the Los Angeles Times.

"But once I posted the comment to Free Republic I was no longer working alone, and that is the real point of the story about the story about the story."

That story began Wednesday, 19 minutes after the 60 Minutes IIbroadcast began, when another FreeRepublic poster, TankerKC, noted that the documents were "not in the style that we used when I came into the USAF. . . . Can we get a copy of those memos?"

Less than four hours later, Buckhead pointed to "proportionally spaced fonts" in the memos, which CBS said had been written in the early 1970s by Bush's commanding officer, Lt. Col. Jerry Killian, who died in 1984. Buckhead concluded that the documents had been drafted on a modern-day word processor rather than a typewriter.

"I am saying these documents are forgeries, run through a copier for 15 generations to make them look old," Buckhead wrote. "This should be pursued aggressively."

And it was - with startling speed.

Early Thursday morning, Minneapolis lawyer Scott Johnson was in his basement home office, preparing to link some morning news reports to the site he co-writes, when a reader sent an e-mail about Buckhead.

Intrigued, Johnson, whose online ID is "The Big Trunk," put a link on his site, PowerLineBlog.com, to Buckhead's post.

Then the floodgates opened.

"Thanks to all the readers who have written regarding this post,"Johnson wrote in an early update. "Several have pointed out that the Executive line of IBM typewriters did have proportionally spaced fonts, although no reader has found the font used in the memos to be a familiar one or thought that the IBM Executive was likely to have been used by the National Guard in the early 1970s.

Single page