A federal judge has tossed a copyright infringement lawsuit filed by a litigation-friendly pornography producer in a rare move that may help other defendants in the growing “BitTorrent” litigation practice in Chicago.

Magistrate Judge Geraldine Soat Brown on Monday issued a summary judgment order in favor of a “John Doe” defendant who had been accused in 2013 of illegally downloading more than 20 of Malibu Media’s adult movies.

The ruling was a rare event in the newly popular practice of “BitTorrent litigation” — where Internet users are sued anonymously for allegedly stealing copyrighted movies. Malibu Media is the most active litigant in a field where economics and social stigma often lead defendants to settle rather than fight.

Malibu Media has filed 5,207 copyright lawsuits in the past four years, according to research firm Lex Machina. Eighty-four percent of those cases “likely settled” and summary judgments have been issued in only two cases, Lex Machina said.

Monday’s ruling, though, vindicated an unnamed man who spent more than two years arguing he never downloaded the porn in the first place.

Malibu Media relies on a German-based technology company that tracks IP addresses — basically signatures of an Internet connection — that participate in illegal downloading over BitTorrent, a common Internet protocol for data sharing.

Malibu Media accused the defendant in Sept. 2013 of infringing 24 of its copyrighted videos.

An expert testified there was no evidence the defendant’s computer ever contained the movies or software to download BitTorrent files.

The defendant argued the movies could have been downloaded by a number of other people, including neighbors or guests who visited him and his wife to see their new child at the time of the alleged downloading.

Brown ruled the evidence and testimony provided by two Malibu Media witnesses could not show the defendant downloaded the movies.

“There is nothing in either declaration that would allow the court to conclude that the ‘bits’ and ‘pieces’ captured by IPP’s technology as allegedly distributed from Doe’s IP address meet the standard of originality justifying a finding that they are protectable elements of the works,” Brown wrote.

Erin Kathryn Russell of The Russell Firm LLC and Jonathan L. A. Phillips of Shay, Phillips Ltd. represented the defendant. Russell said the pair considered the judge’s ruling “fair.”

“The most important thing to take from the ruling is plaintiffs do have to have evidence to bring their claims,” Russell said. “Judge Brown made that evident in her ruling and we think that’s a very important factor for these cases going forward.”

Jeffrey J. Antonelli, who represented a neighbor of the defendant who was deposed in the case, said that portion of the ruling could help other defendants who choose to fight Malibu Media’s lawsuits.

But he cautioned it would not likely result in fewer lawsuits filed by Malibu Media.

The ruling likely means Malibu Media will have to produce expert testimony in order to show that the evidence it relies on to file the lawsuits leads to videos being watched by the defendants, Antonelli said.

“The real problem, of course, is most people can’t afford to get to the summary judgment stage even if they’re innocent,” he said.

Malibu Media has 113 pending cases in the U.S. District Court for the Northern District of Illinois, according to Lex Machina.

Mary K. Schulz, the lead attorney for Malibu Media, did not return a request for comment.

The case is Malibu Media LLC v. John Doe, No. 1:13-cv-06312.