Pinterest is now the number three social networking site, according to new data from Experian. Like Facebook and Twitter before it, Pinterest created a social network complete with a verb particular to the site itself: Pinning. Nowhere else on the social Web can you "pin" content - except, of course, on Pinterest knock-off type sites, or on sites that send content to Pinterest itself.

Take PinAQuote.com, for example. It is a site that allows users to grab a quote from somewhere on the Web, and quickly pin it to Pinterest. Or PinCat, a site which lets you choose from many lovely cat photos, pinning them to Pinterest. Of course, you can Instagram or tweet that kitty, but it's just not as exciting as pinning it. Why would you give a cat a bird when you could pin it up, like a pin-up girl?

Yet for all the lovely cats on the Internet, users aren't satisfied just looking at furballs. They want balls, they want boobs. And just as there are plenty of boobs on Facebook and spambots on Twitter, there was bound to be a porn-irific knockoff of Pinterest. Pornterest is what we all thought it would be called. But that's not what happened.

Snatchly.com calls itself the "Pinterest for Porn." Just as Pinterest offers a "pin it" button for your browser, Snatchly.com offers a "snatch it" button, which helps users grab an image or video, and quickly pin it.

Like Pinterest, Snatchly is not a producer of the content found on the site. Furthermore, it requires all users to identify where they found the images they pin. It requires users to be at least 18 years old in order to upload images and videos, and that person must verify that the models in the images are at least 18 years of age, as well.

This reminds me of IsAnyoneUp.com, the site for anonymously publishing nude photos. Users submit images of themselves, their friends and people they know, not always with their consent. This makes IsAnyoneUp.com a site of contention for many - and owner Hunter Moore has received plenty of flak for making money off of other peoples' nudie pics.

What of copyright issues? Do Internet users who are busy watching animated GIFs of porn have more than three seconds of thought about a copyrighted image? Snatchly says that in accordance with the Digital Millennium Copyright Act of 1998, it will "respond expeditiously to claims of copyright infringement committed using the Snatchly website." So if your private parts end up on Snatchly, just write and let them know.

"If a user owns the material in question, we will remove it," says Snatchly's Neil Notts. "If they don't own the material but can make a reasonable claim that it is in fact them, we may be willing to contact the owner on their behalf and request removal." He adds: "We are very sensitive to concerns of material posted on Snatchly."

The act of "pinning" offers social media users yet another way to indicate a tiny amount of interaction, one that is even more effortless than a Facebook like or a Twitter tweet. It is a "pin," a momentary click and reshare, a return to the ease of the pin-up image, which can come from any variety of mediums - magazines, newspapers, postcards or even lithographs. Today the pin-up re-emerges, thanks to Pinterest and knockoffs like it.

Lead image via Flickr. Cat image via PinCat.