So far, there's no video, but a supposed nude photo of Justin is floating around Twitter and Tumblr. Before you get too excited, the naked guy's head is cropped out of the photo, so there's no way to prove anything. But in case you're interested, a quick Google search will get you there.
OK, let's talk about this. Justin Bieber does have a bird tattoo on his hip. Of course, that's exactly the kind of detail that even a Photoshop novice could add to the pic. Also, closer inspection of the tattoo — hey, I'm just doing my job — reveals that it doesn't quite match. It could be the quality of the nude pic, but it's more likely just not the same tattoo.
Is Justin Bieber uncircumcised? That's tougher to say. According to the quite possibly reliable A Gallery of Famous Intact Men, he is, in fact, uncut. Their source: "My nephew went to school with him." Good enough.
But the most damning evidence against this being an actual photo of Justin's junk is that the same pic apparently existed on Tumblr before anything was stolen. Amelia McDonell-Parry at The Frisky says she saw it in a blog post from 10 months ago.
To conclude, all we really know is that it's a penis, and that Justin Bieber's "personal footage" was stolen. Also, Justin Bieber has a dumb tattoo.
UPDATE: As many commenters have pointed out, the bellybuttons do not match, so we can say conclusively that the naked guy is not Justin Bieber. Because some people were concerned about the age of the person in the nude photo, it has been removed.