The Motion Picture Association of America said Friday intellectual-property holders should have the right to collect damages, perhaps as much as $150,000 per copyright violation, without having to prove infringement.

"Mandating such proof could thus have the pernicious effect of depriving copyright owners of a practical remedy against massive copyright infringement in many instances," MPAA attorney Marie L. van Uitert wrote Friday to the federal judge overseeing the Jammie Thomas trial.

"It is often very difficult, and in some cases, impossible, to provide such direct proof when confronting modern forms of copyright infringement, whether over P2P networks or otherwise; understandably, copyright infringers typically do not keep records of infringement," van Uitert wrote on behalf of the movie studios, a position shared with the Recording Industry Association of America, which sued Thomas, the single mother of two.

A Duluth, Minnesota, jury in October dinged Thomas $222,000 for "making available" 24 songs on the Kazaa network in the nation's first and only RIAA case to go to trial. United States District Court Judge Michael Davis instructed the 12 panelists that they need only find Thomas had an open share folder, not that anyone from the public actually copied her files.

(It is technologically infeasible to determine whether the public is copying an open share folder, although the RIAA makes its own downloads from defendants' share folders, produces screen shots and, among other things, captures an IP address. An Arizona judge ruled last month in a different case that those downloads count against a defendant, a one-of-a-kind decision being appealed on grounds that the RIAA was authorized to download its own music.)

Judge Davis suggested last month that he might have erred in giving that "making available" jury instruction, and invited briefing from the community at large. A hearing is set for August, and the judge is mulling whether to order a mistrial.

The deadline to submit briefs to the judge was Friday. Among the briefs, the Electronic Frontier Foundation, Public Knowledge, the United States Internet Industry Association and the Computer and Communications Industry Association all jointly filed a brief, saying the law did not allow damages for "attempted" copyright infringement.

"Given the serious consequences that flow from copyright’s strict liability regime, the court should resist plaintiffs imprecations to expand that regime absent an unequivocal expression of Congressional intent," the groups wrote, noting that the language in the Copyright Act demands actual distribution to the public of protected works.

It was a similar brief in tone to the one that a group of 10 intellectual property scholars lodged earlier in the week.

But the MPAA, long an ally to the RIAA, which has sued more than 20,000 individuals for file sharing of copyrighted music, told Judge Davis that peer-to-peer users automatically should be liable for infringement.

"The only purpose for placing copyrighted works in the shared folder is, of course, to 'share,' by making those works available to countless other P2P networks," the MPAA wrote.

Other groups meeting Davis' deadline include the Intellectual Property Institute at William Mitchell College of Law and the Progress & Freedom Foundation.