(01-07) 20:04 PST -- In a case that could chill free speech online, a San Francisco chiropractor has sued a local artist over negative reviews published on Yelp, the popular Web site that rates businesses.

Christopher Norberg, 26, of San Francisco posted the first review in November 2007 after visiting Steven Biegel at the Advanced Chiropractic Center on Valencia Street. In the six-paragraph write-up, Norberg criticized Biegel's billing practices and said the chiropractor was being dishonest with insurance companies.

When the chiropractor complained about the review, Norberg replaced it with a new entry a few weeks later that read in part, "I think that he is trying to scare me into removing a negative post (that might explain why he has only positive ones). I believe that he has been harassing me into shutting up, and I feel as a consumer I have a voice and that I can use it on forums made for sharing it, especially when I feel that the experience was unsatisfactory."

Biegel said both reviews were malicious and in February sued Norberg for libel and invasion of privacy. If the case isn't settled, it will go to trial in March in San Francisco Superior Court.

"I'm not looking for my 15 minutes of fame," Biegel said Wednesday. "This suit was filed after a year of trying to resolve this. I am a proponent of free speech, but at the same time, individuals have a responsibility when they publish something as to the accuracy of it."

The case raises questions about whether people can use the Internet to express negative feelings about others and also about the long-term viability of businesses like Yelp that publish third-party reviews, even though Yelp - under the federal Communications Decency Act - is not responsible for the content it publishes.

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