Did you hear? Britney Spears had a fatal run-in with a pretzel, a guy named Homosexual ran in the Olympic 100-meter dash, and President Obama attended a Muslim academy.

What--You missed that news? Well, that might be because all those stories are untrue. But that didn't stop them from appearing on the Web, and in some cases, on reputable and popular sites.

Nobody's perfect, of course. But on the Web, imperfection can come at a high price: false news reports can torpedo a stock, harm someone's reputation, or reduce fans of a supposedly dead celebrity to tears. As news publishing systems become more automated, they're easy prey for hackers, hoaxers, and half-assed algorithms. Or they can be done in by human error, magnified a million times by the viral nature of the Net.

"Once something is online and people start finding it, it's just a matter of time before it starts spreading through links, blogs, Twitter, e-mail, or IM," says Craig Silverman, editor of Regret The Error, which tracks journalistic goofs. "The Web is a fantastic medium for making information go viral. It's also a great tool for fact checking. Unfortunately, the latter takes more time to do, and a lot of people--journalists included--link before they think to check something out."

The results can be humorous or disastrous; they can lead to fake death notices or fiscal debacles. Here are our picks for the Web's ten biggest snafus.

10. What are they, nuts?

February 2009: Here's the setup for a joke: What do Fox News, Attorney General Eric Holder, and a rare monkey have in common? Answer: They unwittingly combined to make the bloggers at Huffington Post look like complete fools.

The story begins with a De Brazza's guenon that escaped from the Woodland Park Zoo in Seattle. Its distinguishing characteristic: a bright blue scrotum. (Don't blame us, we're not responsible for evolution.) The primate's privates made for lively chatter on Fox News, which also reported on the AG's controversial statement that the US is "a nation of cowards" when it comes to race relations.

John Sanders, a tech reporter for WBAL-TV in Baltimore, decided to splice the two reports together and post the video on YouTube, making it appear as if Fox News commentator John Gibson was talking about the attorney general's "bright blue scrotum." That clip made it to TVNewser, where a HuffPost blogger found it and broadcast it to the world, not realizing it was just a hoax.

Huffington later apologized for getting so badly duped. The monkey was captured about 45 minutes after its escape, and Sanders lost his job over the joke gone sour.

9. Amazon is no friend of Dorothy

April 2009: Hell hath no fury like several thousand gay and lesbian people scorned, as Amazon learned earlier this month when a cataloging error made the World's Biggest Store look like the World Biggest Homophobe. Automated software used by the online retailer to make porn harder to find on its site ended up shoving a number of books on LGBT themes into the closet.

According to a report by Andrea James at the Seattle Post-Intelligencer, an Amazon employee in France mistakenly tagged some 57,000 books as "adult," causing them to be removed from the site's sales rankings and search results. An Amazon spokesperson apologized for the "embarrassing and ham-fisted" mistake and says the problem is being fixed. But Amazon has yet to adequately explain why titles like Heather Has Two Mommies got delisted, while A Parents' Guide to Preventing Homosexuality did not.

8. Pop tart collides with pretzel van

June 2001, October 2001: Poor Britney Spears. The troubled pop diva was killed twice in the space of six months by hoaxes picked up by mainstream media. In the first story, Spears was killed when a car driven by former boytoy Justin Timberlake collided with a pretzel van. The story--which may have started as a "joke" news report on KEGL radio in Dallas--migrated to online message boards and was posted to a fake BBC site, prompting thousands of phone calls to Los Angeles police and fire departments.

Brit bit it again in another road mishap (this time minus the snack foods). It appeared on a bogus CNN.com page created by Michigan comic-strip artist Tim Fries, who wanted to make a point about how fake news can spread across the Web.

Fries used URL trickery to make it look as if the story was hosted by CNN, and exploited a bug in CNN's "email this" feature that caused it to be the site's "Most Popular" news story, even though it never actually appeared on CNN.com. Some 120,000 Netizens clicked on the link and mourned Spears' passing, however briefly.

Spears is hardly the only celebrity to get killed by the Web (see "The Dead Pool," below). But please, people, can't we just leave Britney alone?

7. Not Gay, just homosexual

June 2008: Tyson Gay is an Olympic class sprinter. But at conservative news site OneNewsNow, he's better known as Tyson Homosexual, thanks to a software filter that automatically replaces the word "gay" with "homosexual" in every news story. The result? Headlines like "Homosexual eases into 100 final at Olympic trials."

Tyson wasn't the only homo sapien to receive an involuntary name change; professional basketballer Rudy Gay also got the OneNewsNow treatment, leading to sentences like this one: "Memphis Grizzlies backers hit the hay hoping that Kevin Love would open things up for Rudy Homosexual in the front court." (Thanks to the Right Wing Watch blog for that juicy nugget.)

The site has since changed its auto-replace software to exclude surnames; so while you may now be Gay on OneNewsNow, you still can't be gay.

6. Meet John Kerry, metrosexual

October 2004: What is it about Fox News and personal grooming? In October 2004, chief political correspondent Carl Cameron posted a fictional news item on FoxNews.com in which then-presidential contender John Kerry is quoted as boasting about being a "metrosexual" who loves manicures.

After other reporters began asking where this story came from, the site pulled the item and posted the following retraction:

"Earlier Friday, FOXNews.com posted an item purporting to contain quotations from Kerry. The item was based on a reporter's partial script that had been written in jest and should not have been posted or broadcast. We regret the error, which occurred because of fatigue and bad judgment, not malice."

A Fox spokesperson noted those responsible had been "reprimanded," but never explained how the report made it onto the site or what punishment Cameron received. As Media Matters reported, Fox commentators brought up Kerry's predebate manicure five times that same night. Apparently, Cameron wasn't the only one suffering from fatigue, bad judgment, or poor cuticle management.