That's Hunter Moore's business model:
Is Anyone Up? is fairly simple in concept: someone anonymously submits nude photos to Moore through the site's submission form. Perhaps it’s a jilted ex, or a recent hookup, or a vengeful friend. These days, the site receives many self-submissions as well. Provenance doesn’t matter. Moore uploads those photos and attaches identifying screen-grabs from the person’s Facebook, Tumblr or Twitter accounts—whatever’s available. He sometimes adds a pithy caption and a reaction gif at the end, usually from a television show or meme. And that’s pretty much it. Is Anyone Up? currently receives, Moore said, 30 million page views a month.
Apparently, what Moore does isn't illegal. But even Gawker thinks this goes too far:
Stalker porn should make you think twice the next time you sext your significant other. It also requires your Facebook account to be wide open, so lock that down tight. The embarrassment of showing up on IsAnyoneUp must be awful—but that's nothing compared to the fact that your mistake is making people like Hunter Moore rich.