A week after its fifth birthday, Tumblr got hit with a grownup copyright infringement lawsuit—and a gnarly one at that.. The plaintiff is porn company Perfect 10, and they sound utterly unapologetic in the case's paperwork. Tumblr, Perfect 10 claims, enabled the "rampant and unremedied uploading, display and distribution of Perfect 10's copyrighted photographs." Not only did Tumblr allegedly ignore six Digital Millenium Copyright Act (DMCA) takedown requests, "Tumblr employees have posted infringing content to Tumblr servers, to help start the business, including content which infringes upon Perfect 10's Copyrighted Works."

There are two things that jump out at us as interesting. First of all, Tumblr is getting sued. Folks have been waiting for a case like this to go to court for years sinceTumblr and similar user-generated content sites live in a relatively grey area of copyright law. Normally, the users themselves are responsible for content uploaded to user-generated sites like Tumblr due to "safe harbor" laws. But as PaidContent's Jeff John Roberts explains, "Websites can lose the safe harbor protection if they fail to remove infringing material or if they have an active role in hosting unauthorized images."  And Perfect 10 is known for aggressively pursuing cases like this.

The second thing is relatively simple: Tumblr ought to think about controlling its porn content. While the site's front-facing image is a haven for hipsters to drool over pictures of fixed gear bicycles and arty landscapes, there's a massive pornographic Tumblr underbelly, and it's likely that instances of copyright infringement aren't limited only to Perfect 10's images alone. It's reasonable to assume that other rights holders will latch on to Perfect 10's case as they find their content hosted on Tumblr's servers. Tumblr could cut its losses now by hiring a moderation team to vet some content before it goes live.

Another fallout from this lawsuit? The parents of the millions of hipster teenagers who keep Tumblr humming will not be comforted to learn that there's porn on their kids' publishing platform of choice. But of course, in that, Tumblr is far from alone.