In a ruling issued late last week, Maryland's highest court ruled against unmasking commenters who allegedly defamed the owner of a local Dunkin' Donuts. The court wrote that the plaintiff in the case, a local businessman, had not presented enough evidence to show that he would be able to prevail in a libel claim at trial.

"On the one hand, posters have a First Amendment right to retain their anonymity and not to be subject to frivolous suits for defamation brought solely to unmask their identity," the court wrote. "On the other, viable causes of actions for defamation should not be barred in the Internet context."

With the decision, Maryland joins courts in Arizona, California, Delaware, New Jersey, New York and Texas, as well as the District of Columbia, that have ruled that anonymous commenters are entitled to legal safeguards before being unmasked, said Sam Bayard, assistant director of the digital rights group Citizen Media Law Project.

Bayard, who has been tracking these cases nationwide, warned that without such legal protections, people might sue to unmask bloggers simply to intimidate them or take other action against them outside of court.

"We need some protection for anonymity because it contributes to public debate," said Bayard. "There is a real risk that people will use the legal process to discover a person's identity, not because they want to pursue a claim, but because they want to retaliate."

The Maryland case stemmed from comments posted to the Independent Newspapers-owned site NewsZap.com about a Centreville, Md. Dunkin' Donuts owned by local entrepreneur Zebulon Brodie. One commenter called the store "one of the most dirty and unsanitary-looking food-service places I have seen," according to court papers. Another post complained about conditions outside the shop.

Brodie filed a lawsuit against Independent Newspapers for defamation on a NewsZap site and also sought to subpoena identifying information about individual commenters.

Brodie's allegations against the site were dismissed under the Communications Decency Act, which immunizes Web sites from libel for comments posted by users. But the trial judge ordered the news company, which collects registration information, to disclose data that would reveal the commenters' identities.

The Maryland Court of Appeals reversed that on the ground that Brodie would not be able to prove that the commenters libeled him. That determination hinged on a technicality: Brodie did not specifically file against the two pseudonymous commenters who wrote about the shop's conditions within the statute of limitations.

Public Citizen, which argued against the subpoena, had urged the court to rule that plaintiffs in defamation must show that the allegedly libelous statements were not true as a condition of unmasking commenters.

Maryland's highest court did not directly state that in its opinion, but did set out actions that courts must take before ordering sites to reveal commenters' identities. The court ruled that commenters must be notified about the proceeding and given an opportunity to respond. Also, courts must examine the allegedly libelous statements, determine whether the plaintiffs have alleged sufficient facts to potentially prove libel, and then balance the commenters' free speech rights against the strength of the libel claim.

This news story is important. I recommend that everyone read it.