Yesterday, at approximately 9:53 am, a headline appeared on Bloomberg screens worldwide stating "UAL Corp.: United Airlines files for Ch. 11 to cut costs." In a blink, the airline's stock fell from around $12 to $3 a share, and Nasdaq quickly halted trading. About an hour later, UAL issued a statement confirming the report was false, and UAL's shares rebounded to close at $10.92.

What mischief caused the company to lose $1 billion in market capitalization? Who was to blame for the false story? A day later it appears that for all of the cries that quickly followed for SEC investigations, litigation and retractions, there were almost no humans involved in the chain of events that almost took UAL's stock to zero yesterday. Call it "Bots Gone Bad."

At 10:36 pm on Saturday, Sept. 6, a Google "bot" (an automated crawler that seeks out new information on the Internet for Google) moseyed on to the Florida Sun-Sentinel website where it discovered a new link in a section labeled "Popular Stories: Business." The link supposedly had not been there during the bot's last "crawl" at 10:17 pm and, seeing the new link appear, the bot followed it to an article titled "UAL Files for Bankruptcy." According to Google, the only date found by the bot for the article indicated that the article was from September 7, 2008.

(Click on the image to see what Google says its bot saw)

The Google bot then indexed the article and made it available through Google News search, placing a fresh date of September 6, 2008 on the article. On Monday morning, a researcher for Income Securities Advisors reportedly found the story after running a search for "bankruptcy 2008" on Google News, according to an article in the Chicago Tribune. The researcher linked to the article on the Sun Sentinel Web site, found the story, and forwarded it to Bloomberg at 9:53 a.m. As discussed above, Bloomberg then reportedly ran the story, with disastrous consequences.

Furious shareholders who lost money when the stock tanked called for an SEC investigation and litigation to recover losses, but it looks more and more like there are no clear-cut bad guys in this equation. Or even any humans at all.

Bloomberg? No one really seems to be blaming it for serving as a conduit of the information. According to the Chicago Tribune, Bloomberg "acknowledged that information delivered to the company's professional news service from suppliers such as Income Securities can go out to subscribers to Bloomberg's professional service without independent verification."

The Sun-Sentinel? Its spokesperson said the story did not appear in Monday's newspaper and existed only in the archives. The spokesperson said that "no one at Tribune Co. had gone into the original story file since it was published, nor had any of its newspapers republished the story over the weekend or Monday."

Income Securities Advisors? Its president acknowledges that their researcher did no independent verification on the story pulled from Google News. "We are a reading service," he was quoted as saying in the Tribune article. "We say, 'This story appeared today in the Sun Sentinel.' I don't think that calls for us to check it out."

Google? That takes us right back to the only truly active player in this mess — a "bot" that has now crawled its way into stock market infamy.