Cyrus Sullivan says he had a nagging feeling while dating a woman last year that she was hiding something from him.

"At first she would mention to me that she had to tell me something," says Sullivan, a 26-year-old Portlander. "But [she] would never actually tell me about it."

When she told him she had herpes, he says it was too late; he came down with the sexually transmitted disease several weeks later.

For Sullivan, revenge meant creating, a website that allows users to post names, locations and pictures of people who users say have sexually transmitted diseases. His ex-girlfriend is one of 27 people from Oregon and 12 people from Multnomah County listed in a searchable database.

"I got screwed while screwing," Sullivan wrote on his own entry, "and want to warn others about people like her."

Since Sullivan created the site last October, users have posted 769 people from all over the world who purportedly have STDs such as herpes, chlamydia and HIV.

Some posts appear to be hoaxes, and others list celebrities or criminals reported by other media to have STDs.

Until June, Sullivan, a freelance programmer, says anyone could post information. Sullivan says he changed that to require users to register first in an effort to reduce the number of fake postings. Either way, Sullivan says he won't remove a name until that person complains, gets tested and has a doctor send the sealed results to Sullivan.

Obviously, this approach upsets some people.

"Now listen up," wrote one angry man to Sullivan, who later posted it on the "Threats, Rants, and Raves" section of his website, "you better take my name off your amateur excuse for a website before you're [sic] a** ends up served and in court. I'm not going to plead with you… You have no right to see my confidential medical records to determine my eligibility to be removed from your website."

So, how is it he hasn't been sued yet? Sullivan and First Amendment attorneys say it's because website moderators are protected under federal law so far from being prosecuted for information posted by others.

However, that still leaves the poster potentially liable. And's terms of use warn users that if they knowingly post false information, they agree to compensate the victim $5,000 plus legal fees.

Sullivan has not moved to collect from any pranksters yet. But he has passed along their Internet service provider numbers to at least four victims. So far, he says, none has followed up with legal action.

Sullivan admits that "like any machine, it can only be as good or as bad as the people using it," and he urges people to "keep in mind that it's there to help people."

That's ludicrous, says Graham Harriman, interim manager of the Multnomah County Health Department's STD, HIV and hepatitis C program. Harriman says fear of being listed on the site could discourage people from being forthright and seeking treatment.

"It's better public health practice to discuss STDs with your partner and practice safer behavior," Harriman says.