YouNow might be the biggest site you've never heard of. It's also supremely creepy.

The live-stream broadcasting (aka live-casting) site-slash-app, lets users perform for viewers all over the world, via the cameras on their computers, tablets and smartphones. Whether you're a singer looking to get discovered, are lonely and bored, or you simply love an audience, YouNow brings those who want to be watched together with those willing to watch them.

A hybrid of sorts between YouTube and live-stream apps like Meerkat and Periscope, YouNow boasts 100 million streaming videos per month. But unlike the popular new apps that people have been using in bursts over Twitter, YouNow encourages long-form streaming, for hours at a time, even while the broadcaster is asleep.

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Testimonials on the site tout that it lets you "meet so many cool people from all over the world," and how friendly the community is. "If you're in a bad mood, just get on YouNow," says Cierra from Little Rock, Ark.

And it's not just a source of entertainment and support, it's also a revenue generator. Fans can purchase points to tip their favorite performers, who split the profits with YouNow.

But for anyone who's left their teenage years behind them -- or who has a teenager of her own -- YouNow has an undeniably discomfiting air. (Remember the feeling you got that time you tried Chatroulette?)

Browsing through the tiles representing various users' streams, there's no ignoring the preponderance of videos that might attract an unsavory set. Take for instance the British 14-year-old streaming in the #truthordare section who, on a recent evening, earnestly replied to a commenter who suggested girls can't make their elbows meet in front of their chests by trying over and over again to do just that, innocently pressing her breasts together each time.

Then there's the #sleepingsquad, a tag denoting broadcasters who leave the camera rolling as they sleep. If you're looking to watch kids alone in their bedrooms at night, this is definitely the easiest way to do it. No tree-climbing or binoculars required -- and you're considered a "viewer" rather than a Peeping Tom.

A near failure that suddenly rose to massive success last year, YouNow might be a perfect example of an Internet company meeting huge demands we never knew were there. As a denizen of the digital age, it's hard to ignore its impact. As an adult in polite society, it's hard to watch. And as a parent, it might just be the most terrifying thing your child is doing while you're not looking, and everyone else is.