In September 2010, Dale Askey, now a librarian at McMaster University, in Ontario, published a blog post titled “The Curious Case of Edwin Mellen Press,” in which he called the Edwin Mellen Press “a dubious publisher.” For a few months afterward, several people chimed in in the blog’s comments section, some agreeing with Mr. Askey, some arguing in support of the American publisher.

In June 2012, Edwin Mellen Press’s founder, Herbert Richardson, issued a notice of action to Mr. Askey, suing him for more than $1-million. That same day, the press issued a similar notice of action to Mr. Askey and McMaster University, telling them that they were being sued for libel and seeking damages of $3-million.

The lawsuit, filed in the Ontario Superior Court of Justice, came to light this week when Leslie Green, a philosophy-of-law professor at the University of Oxford, mentioned the case when responding to a blog post about a list that gave Edwin Mellen Press a low ranking among philosophy publishers.

“My own view is this is intolerable,” Mr. Green said in an e-mail interview. “McMaster University should vigorously defend its librarians, and academic freedom. In my opinion, there is no merit whatever in Mellen’s lawsuit against the university: It is a bullying tactic.”

Other professors have also come to Mr. Askey’s defense. Martha J. Reineke, a professor of religion at the University of Northern Iowa, started an online petition asking for an end to the lawsuit. In its first hours online, it drew more than 50 signatures.

In a copy of the press’s notice of action obtained by The Chronicle, the publisher alleges that Mr. Askey accused the press of “accepting second-class authors” and urged “university libraries not to buy the Press’s titles because they are of poor quality and poor scholarship.”

Edwin Mellen Press also charges that because McMaster University employs Mr. Askey and did not require him to remove the blog post or the comments, then the university “adopted the defamatory statements as their own.”

Altogether, Edwin Mellen Press is asking for $3-million in damages for libel and $500,000 in aggravated and exemplary damages. Mr. Richardson is asking for $750,000 in damages for libel and $300,000 in aggravated and exemplary damages. The press also asserts that the defendants are liable for statements made by others in the comments section of the blog post, including one scholar’s claim that Edwin Mellen officials “practically enslave their authors to a contract that NO ONE should ever sign.”

James Turk, executive director of the Canadian Association of University Teachers, said that while it may seem odd that someone can be sued for statements they didn’t even make, user comments are “not a completely clear area of law.”

“The more monitored user comments are, the more I may be liable for it,” Mr. Turk said. “If I leave up comments that have been asked to be taken down, then I can be sued, and probably successfully.”

The notice goes on to allege that the press asked McMaster to remove the post and for an apology, but that the university did not oblige and then “pursued an Internet campaign to put the Press out of business.”

The blog post was removed in March 2012, but a copy of the post, including the comments section, was attached to the notice of action. The post and several comments alleged that Edwin Mellen Press, while occasionally publishing “a worthy title,” mostly publishes “second-class scholarship” at “egregiously high prices.”

“Given how closely Mellen guards its reputation against all critics, perhaps I should just put on my flameproof suit now,” Mr. Askey added at the end of the post.

Edwin Mellen Press does have a history of being combative toward critics. The publisher once sued Lingua Franca for libel when, in a 1993 article, the now-defunct magazine criticized the company. Edwin Mellen did not win, but it did later publish a book about the lawsuit, which can be purchased for $119.95.

In an October 2012 newsletter, the publisher urged its authors to fight “false and malicious comments” being published on the Internet, including in a Chronicle of Higher Education forum thread.

“We do not know why the criticism persists, but this problem has gone on for some time and has done a great deal of damage,” the newsletter read.

The lawsuit is “a classic SLAPP suit,” Mr. Turk said.

“It has the effect of simply trying to silence somebody,” he said. “The lawsuit itself seems to be one without merit in the sense that what Askey was saying seemed to be fair comment dealing with a public-policy consideration that’s highly relevant to academic librarians. What academic librarians do is assess what books libraries should and shouldn’t acquire.”

The Canadian faculty association heard about the case earlier this week, Mr. Turk said, and will now be working with Mr. Askey. Mr. Turk said he felt as if the university should be doing more to defend its librarian, the same way a newspaper might defend one of its reporters. Mr. Askey is paying all of his own legal expenses.

Mr. Askey said he was “shocked and dismayed” by the lawsuit, as he feels he was just doing his job.

“At the time I wrote the post, the work I was doing in libraries was directly related to assessing materials for potential inclusion in the library collection,” Mr. Askey said. “It was, as such, my job to assess the quality of books, and I did so based on many years of experience in the field.”

Further complicating the matter, Mr. Askey was not even a librarian at McMaster when he posted on the blog. He was still an associate professor at Kansas State University, working in Hale Library, he said. He started working at McMaster in February 2011.

McMaster released a statement on Friday saying the university strongly “supports the exercise of free speech as a critical social good.”

“For this reason, McMaster University has for more than 18 months rejected all demands and considerable pressure from the Edwin Mellen Press to repudiate the professional opinions of university librarian Dale Askey, notwithstanding the fact that those opinions were published on his personal blog several months before he joined McMaster,” the university stated. “Because of our respect for individual freedom of speech, the University finds itself today a co-defendant with Mr. Askey in a legal action brought by the Edwin Mellen Press.”

Mr. Turk said the statement does not offer enough support for Mr. Askey.

“They didn’t repudiate him, but they aren’t supporting him,” Mr. Turk said. “What they’re ducking here is the central thing that they are being asked to do. They are dodging it. They’re being silent on their actual tangible support, covering the legal costs.”

Edwin Mellen Press did not immediately respond to several requests for comment.