Kathy Sierra's blog, Creating Passionate Users, is filled with musings on software design. Not the kind of thing you'd expect to draw death threats.
But cyber-bullies posted such vicious remarks about her on the Internet that she canceled her keynote speech at a technology conference in San Diego this week, afraid to leave her home in Boulder, Colo.
"I will never be the same," she wrote, then said she had suspended her blogging.
The threats and vivid sexual taunts aimed at Sierra -- and the subsequent uproar -- exposed a creepy reality: Cyber-bullies, often emboldened by anonymity, target bloggers who write about even the most innocuous subjects.
"Certainly you need a thick skin if you're going to blog, but you shouldn't also need a bulletproof vest," said Josh Bernoff, a Forrester Research analyst who received death threats in December after suggesting that Apple Inc.'s music sales were leveling off.
Sierra, a former video game developer, speaks at conferences, co-writes the "Head First" series of books on Web design and blogs about making software more user-friendly. Her case offers another reminder of how uncivil the Internet can be.
The ordeal began four weeks ago, when someone posted this comment on her blog: "I hope someone slits your throat." The writer didn't indicate why.
A few days later, a photograph of Sierra juxtaposed with an image of a noose appeared on MeanKids.org. The caption read, "The only thing Kathy Sierra has to offer me is that noose in her neck size."
Sierra contacted the owner of the site, Frank Paynter, a technology consultant and blogger. Sierra says he apologized and told her he didn't know who posted it, then he took down the entire site.
When contacted by The Times, Paynter requested questions via e-mail, then didn't respond to them.
"MeanKids was purposeful anarchy," he explained on his blog. "I thought the people at MeanKids would create art and criticism, pointed and insulting satire, but not foster a climate of fear."
Another photo of Sierra, doctored to look as if she had underpants over her nose and mouth, popped up on a site founded by Chris Locke, coauthor of "Cluetrain Manifesto," a bestselling book about how the Internet is changing the way corporations do business.
In an interview, Locke said he didn't know who posted the photo or the misogynistic comments but said he hoped the authors would fess up.
"The stuff was despicable -- no argument," he said. "We're trying to get people to raise their hands and say who posted what."
Spooked, Sierra canceled all public appearances. "I am afraid to leave my yard," she wrote Monday on her blog, spelling out what had happened and quoting some of the most offensive comments.
Sierra's experience fast became a hot topic on the Internet. Her posting about the incident had received 1,166 comments by Wednesday, most of them positive but some vitriolic.
She decided to block comments after someone posted -- on Sierra's own blog -- her Social Security number and home address and alleged that she had been the victim of domestic abuse, which Sierra said was absurd.
"Had I known this would have been the reaction, I never would have made that post," Sierra said. "This has just made me into more of a target."
Sierra said she had generally avoided controversy on her blog and couldn't understand why she became the object of abuse. Ironically, her most divisive posting was one that called for more civility. A year ago, she sided with popular tech blogger Robert Scoble's decision to delete personal attacks posted by his readers.
But sometimes a high profile, like the one Sierra enjoys among Web and software designers, is enough to attract abuse. The Internet has made minor celebrities of many people who write passionately about their chosen topics. Some of their readers return the passion, firing back with the same heat that's normally directed at movie stars or politicians.
"Kathy's a celebrity in her own world," said Julian Dibbell, a journalist who has written books about online communities. "That makes her a classic target. She's very warm. She inspires people. She's open-hearted. She's a cute kitty. She's perfect for stomping on."
Online bullying is nothing new. One of the earliest forms of digital harassment took place in 1993, when a player in a text-based virtual world called LambdaMOO wrote in graphic detail how he was "raping" a female character.
Ever since, games, message boards and other online forums have been plagued by so-called trolls, who enjoy provoking other people. MySpace and other sites popular among children and teenagers also attract rabble-rousers.
"We see a lot of this stuff," said Brandon Watson, chief executive of IMSafe Inc., a Houston software company that helped parents flag potential online predators and bullies.
"Kids will leave nasty comments, send anonymous instant messages, create fake MySpace pages that make fun of people, hack into e-mail accounts and send out nasty mail. It's very challenging."