From a long but really interesting article about the site:

I spoke with Moore at length over the phone several times in the past few weeks. While his conversation is peppered with “dudes” and “motherfuckers,” under all that seeming casualness he is clearly shrewd when it comes to business matters and the Internet. He's aware he could be capitalizing on advertisements and bringing in a lot more money, but for now he enjoys the freedom that the lack of advertisers gives him.

[...] Moore walks a legal tightrope that so far has him on the right side of the law. His pictures are all legally acquired. And he never assumes ownership. Yet, as dismaying as it may be for those behind the flurry of public inquiries about why Moore is not in jail, he is not breaking any law.

[...] "Is Anyone Up?" is protected by Section 230 of the Communications Decency Act of 1996. The act provides immunity for Internet service providers—which is interpreted as including websites and blogs—who publish information provided by others. As long as Moore’s material is not illegal, such as child pornography, or copyrighted images, he is not liable. (Free takeaway lesson: file copyright take-down complaints, not defamation claims.)

[...] Now that Moore has linked the commenting system to Facebook, an extended network has formed, one that actively encourages participation and connections. Among many of the commenters and postees I spoke to there's a strong feeling of community. They like IAU: They get to see members of their favorite bands naked and sometimes people they know. Twitter is awash with tweets about people bumping into someone from IAU, or seeing their cousin or former high school classmate on the site. People often check and re-check the site to see if pictures of anyone they know have been posted

[...] Moore makes no apologies or attempts to rationalize what he does. “What do I have to defend myself against? It comes down to, you’re fucking stupid and I’m making money off your mistakes. It might sound rough, but how else are you going to learn not to do this again? It’s like you’re playing Russian Roulette like, oh, let’s hope this doesn’t get out.”

[...] Moore said to expect bigger things in the future. “I have some crazy shit that will change the world. It will be on TMZ. Big celebrities have sent me bigger celebrities, but as of now I’m not going to do that.”

[...] Besides that, he’s working on starting a nonprofit to combat underage sexting. He plans on organizing lectures at local schools about the damage it can do. “My site is already an education on technology, how people abuse it. I think it’s dangerous to give any underage kid a cameraphone,” he said. He seemed serious.

As for advice for those who've had their pictures posted and aren't happy about it, Moore is his usual dismissive self. “Once you’re on page two, nobody gives a fuck anymore.”