Facebook is trying to shut down IsAnyoneUp.com, a sleazy porn site built around posting the Facebook profiles of its often-unwilling subjects. But the site's owner says he's not going anywhere.

Is Anyone Up (NSFW) has capitalized on a new genre of amateur erotica: Stalker porn. It features user-submitted nude cell phone pics, along with screenshots of the subjects' real Facebook profile. Many of Is Anyone Up's models are being exposed on the site without their consent, their private sexts submitted by vengeful exes.

Unsurprisingly, Is Anyone Up has now landed in Facebook's crosshairs. On Tuesday, Facebook's lawyers sent Moore a three-page Cease & Desist letter (PDF), demanding he remove all Facebook content. "Your actions are illegal and must be stopped immediately," the letter, from Joseph P. Cutler of the law firm Perkins Coie, states. (Cutler confirmed he sent the letter on behalf of Facebook, but wouldn't comment beyond that.)

"Facebook will take whatever measure it believes are necessary to enforce its rights, maintain the quality of the site, and protect its users," Cutler writes. Good luck with that.

"I replied with a picture of my dick," Hunter Moore, Is Anyone Up's 25-year-old founder and owner told us in a phone interview. "I'm not a virgin to cease and desists—I get about a million a day. I think [Facebook] is under pressure from users to do something about me… I don't give a fuck. I'm never going to stop."

Facebook says Moore is violating some little-known policies prohibiting the publishing of Facebook profiles without their owners' written consent, and "threatening, harassing or intimidating" Facebook users. The letter demands that Moore remove all Facebook profiles and leave their users alone. Facebook has disabled Moore's personal account to keep him from using the social network as his personal porn recruiting ground, and he says they somehow instantly squash the new ones he creates to check the accuracy of submissions, even though he uses fake names and hides his IP address.

The letter comes after a spate of national publicity which included local Fox News reports and Moore's appearance on Anderson Cooper's daytime talk show, where he was confronted by people whose lives have been screwed up by his site. Moore says Is Anyone Up's traffic is now around 230,000 unique visitors a day, up from 160,000 at the time we wrote our first post about him last month.

As vile as Moore's site can be—one regular feature called "Daily Gnargoyle" makes fun of ugly submissions—it's hard to see how what Moore is doing is illegal, at least as Facebook frames it. (Kashmir Hill of Forbes has outlined the complicated legalities of Is Anyone Up.) We'd rather have Moore ruining unscrupulous sexters' lives than give Facebook's impenetrable terms-of-service the weight of law.

Then there's Mark Zuckerberg's own history of sketchily repurposing other people's pictures. In 2003, he infamously launched Facemash while still a student at Harvard. The site let users vote on female students' attractiveness, without their consent.

Zuckerberg and Moore may soon have more in common than getting rich off violating everyone else's privacy. Moore says he's launching his own social network in January, which sounds like it's going to be an advanced version of the location-based dating app Grindr, but not just for gays.

"It's going to change the game, I guess," Moore said. "It's going to bring social networking back." Right, because Moore is definitely someone you should trust with your personal information.