In a case that ought to send a big “Whoa Nelly” through the blogging world, one blog administrator is being sued or comments made by his site’s visitors.

Traffic-Power.com1 sued Aaron Wall, who maintains a blog on search engine optimization— tactics companies use to get themselves to appear higher in searches at Google, Yahoo and elsewhere — alleging defamation and publication of trade secrets. The suit, filed in a Nevada state court earlier this month, also listed as defendants several unnamed users of the blog.

At issue are statements posted in the comments section of Mr. Wall’s blog, SEOBook.com. Many blogs allow readers to post comments, often anonymously, and Mr. Wall’s blog included several reader submissions that blasted tools sold by Traffic-Power.com.

Traffic-Power.com said in the suit that confidential information about the company has been published on the blog, and it accused Mr. Wall of publishing “false and defamatory information,” but it didn’t identify any of the material in question.

Wall says on his website, “I still do not think I knowingly stated anything wrong or dishonest, and Traffic Power has yet to give me any specific advice of what I should be removing or fixing, other than ‘everything,’ which clearly makes it a free speech issue in my mind.”

From the Wall Street Journal, via Media Channel.