An ex-Congressman in New York successfully unmasked an online commenter at a site run by The Journal News by alleging that the commenter made defamatory posts. But when former Rep. Richard Ottinger and his wife, June, subsequently filed a $1.5 million libel lawsuit, the court threw out the case as barred by a New York law that limits defamation suits when people comment on matters of public interest.

The Ottingers "failed to demonstrate that their action has a substantial basis in fact and law," Westchester judge Richard Liebowitz wrote in a recent ruling.

The case grew out of a zoning matter in Mamaroneck, where the Ottingers had sought building permits to renovate their house. Some neighborhood activists alleged that the village was treating the Ottingers' application differently than other applications, Liebowitz wrote in his opinion.

One opponent said at a televised meeting that a deed regarding the Ottingers' property was "fraudulent" and "invalid," according to the legal documents. The next day, similar comments appeared on The Journal News site LoHud.com, according to Liebowitz.

The posts prompted the Ottingers to seek a court order requiring the Journal News to identify the source of the comments. In June of 2008, Judge Rory Bellantoni in White Plains ruled that the Ottingers had sufficiently shown they could bring a viable defamation lawsuit and ordered the newspaper to reveal any registration information, email addresses and IP addresses associated with the comments.

The commenter turned out to be Stuart Tiekert, a neighbor of the Ottingers, who posted remarks under three different screen names.

The Ottingers followed through by suing Tiekert. But late last month, Liebowitz dismissed the case under New York's anti-SLAPP (Strategic Lawsuit Against Public Participation). That law says that people can't recover for damages libel when the allegedly defamatory statements involve matters of public interest unless the speakers have "actual malice" -- defined as knowing the statements are false or recklessly disregarding the statements' falsity.

First Amendment lawyer Sam Bayard, assistant director of the Citizen Media Law Project, says that the dismissal isn't necessarily inconsistent with the earlier finding that the Ottingers had presented sufficient facts to prove libel. That's because, in some circumstances, litigants are not in a position to prove that a speaker acted with actual malice without knowing the person's identity.