The MPAA and Kickstarter are among those duking it out at the 9th Circuit over the implications of website content moderators.

Hollywood and tech companies are weighing in on a dispute involving photographs of Katy Perry in a bikini and Beyonce Knowles showing off her baby bump. A court ruling last September received scant attention, but now that the case is on appeal, it's setting off some jockeying to influence interpretation of copyright law.

Mavrix Photographs, a litigious paparazzi shop, sued LiveJournal after some of its images of stars ended up on the blog, "Oh No They Didn't!" The blog is a popular one, with over 99,000 members, and users upload content with nine moderators overseeing the community and reviewing posts submitted to a queue.

When photos of Perry, Knowles and other celebrities ended up on the blog, Mavrix skipped past a DMCA takedown notice to sue LiveJournal for infringement based on the actions of its users. U.S. District Judge Cormac Carney granted the defendant's motion for summary judgment on September 19, 2014.

LiveJournal "merely provides an online platform and makes the platform available to members of the public to create their own individual or communal blogs," wrote the judge in his opinion. "Before this lawsuit was filed, LiveJournal did not know of the allegedly infringing posts and was not aware of 'red flags' of specific infringement; it did not have the right or ability to control such infringing activity; and upon learning of the posts it promptly removed them from the site. Consequently, LiveJournal is entitled to the protection of the Digital Millennium Copyright Act safe harbor."

This case deals with the requisite knowledge by an Internet service provider to hold liability for the actions of its users. That's been a topic of interest in the tech and entertainment industries dating back to the legal war between Viacom and Google over content posted to YouTube. That case settled, but other cases look to pick up the thread of unsettled law. In New York, for example, the 2nd Circuit will be ruling soon on record companies pursuing Vimeo.

Mavrix v. LiveJournal is shaping up to be the West Coast edition.

In late April, the Motion Picture Association of America submitted an amicus brief.

"If the record supports Mavrix’s allegations that LiveJournal solicited and actively curated posts for the purpose of adding, rather than removing, content that was owned by third parties in order to draw traffic to its site, LiveJournal would not be entitled to summary judgment on the basis of the safe harbor," said the film industry's trade association.

The MPAA argued that a website that adopts rules on submissions that practically ensures infringing content and has moderators who function as active gatekeepers can't claim they are committing "storage at the direction of the user." Additionally, the MPAA says a website playing a personal role in curating material likely to infringe may rise to "red flag knowledge." Finally, the MPAA asserts that when acting as a gatekeeper that reviews individual posts for the ability to draw visitors, a website may show the “right and ability to control” infringing material.

Here are the less condensed arguments submitted on behalf of the MPAA by Kelly Klaus at Munger, Tolles & Olson.

Among those arguing in the other direction are Kickstarter, Etsy, Pinterest and Tumblr, which submitted its own amicus brief on Monday. They tell the appeals court that Internet service providers should be able to maintain moderators who screen out objectionable material like obscenities and hate speech as well as organize user-submitted information without putting safe harbor from liability at risk.

"While Congress intended the DMCA to make room for these voluntary forms of content review, Mavrix seeks to undermine it," they argue. "Mavrix’s efforts are misguided and, if adopted, would have pernicious consequences for online services and their users."

More specifically, if by playing gatekeeper in any form means becoming knowledgeable enough about infringing material to disqualify safe harbor, these tech companies say the would be left with the "perilous choice" of either being under-assertive or over-assertive with regards to user-submitted content.

"The first would leave online services toothless against even the worst kind of anti-social material, while making it more difficult for users to find useful content," the brief states. "The second would punish innocent users, silence a host of lawful speech, and erode the open nature of the Internet."

Here's the full brief in support of LiveJournal, authored by Brian Willen at Wilson Sonsini.

Oral arguments haven't yet been scheduled.