Prominent blogger Kathy Sierra cancelled a workshop she was scheduled to give today at O'Reilly's Emerging Technology Conference in San Diego and suspended her blog because of death threats she received on her blog and threats of violence posted on other blogs, she said.

Sierra, who keynoted at this year's linux.conf.au in Sydney, runs the Creating Passionate Users blog. (Editor's note: the site now includes the graphic language and photos that Sierra said caused her to pull out of the conference). She also is the co-creator of the Head First computer book series and founder of the popular JavaRanch programmer site.

For the past four weeks, Sierra noted on her blog, she has been getting death threats on the blog. But what prompted her to cancel all her public speaking appearances and contact police, were "disturbing threats of violence and sex posted on two other blogs," according to the blog. Both of those blogs, meankids.org and Unclebobism, have been taken down.

One of the sites posted a photo of a noose next to Sierra's head, she said, with a threat of violence. The other site includes an altered photo of her with inappropriate sexual remarks. That photo appears on Sierra's blog posting where she details the threats.

"I do not want to be part of a culture--the Blogosphere--where this is considered acceptable," Sierra noted on her blog. "Most of all, I now fully understand the impact of death threats. It really doesn't make much difference whether the person intends to act on the threat... it's the threat itself that inflicts the damage. It's the threat that makes you question whether that 'anonymous' person is as disturbed as their comments and pictures suggest."

Robert Scoble, a former technical evangelist at Microsoft and popular blogger, noted that he too has received threats but has just ignored them.

"I am physically ill after reading what happened to Kathy Sierra," Scoble noted in his blog. "The Internet culture is really disgusting. It's this culture of attacking women that has especially go to stop. Whenever I post a video of a female technologist there are invariably are snide remarks about body parts and other things that simply wouldn't happen if the interviewee were a man."