Last Wednesday, BuzzFeed’s Jack Shepherd published an irresistible piece called, “21 Pictures That Will Restore Your Faith in Humanity.” The post is exactly as advertised, a rundown of photos of people being more wonderful than you’d expect—rescuing animals from danger, helping strangers in need, expressing tolerance for others, and all manner of additional good stuff. It became an instant hit on Reddit, Twitter, and especially Facebook, where it has earned more than 2 million Likes. So far, the post has attracted more than 7 million views, and as of Tuesday morning, its traffic shows no sign of abating.

When I saw Shepherd’s piece, my first thought was, Why didn’t I think of that? It’s a question that often pulls at me when I point my browser to BuzzFeed, which I do many times a day. Like a modern-day, unstuffy Reader’s Digest, BuzzFeed has a knack for distilling the good and the bad of life on the Internet into short, fun, highly clickable vignettes.

How does this one site come up with so many simple ideas that people want to spread far and wide? What’s their secret?

The answer, in short, is that BuzzFeed’s staff finds stuff elsewhere on the Web, most often at Reddit. They polish and repackage what they find. And often—and, from what I can tell, deliberately—their posts are hard to trace back to the original source material.

Take that “Faith in Humanity” write-up. Last September, NedHardy.com—“the self-anointed curator of the Internet,” a kind of poor man’s BuzzFeed—posted an item called, “7 Pictures That Will Restore Your Faith in Humanity.” Then, last month, NedHardy posted another piece, “13 Pictures To Help You Restore Your Faith in Humanity.” Half of the photos in BuzzFeed’s post appear in NedHardy’s two compilations. NedHardy isn’t mentioned anywhere in BuzzFeed’s “21 Pictures” post.

Once BuzzFeed had the germ of the idea, finding more pictures to populate its list was a matter of simple searching. A Reddit query for “faith in humanity” turns up most of the rest of the images in its list. Still, I was left guessing at the source for the two most iconic pictures in BuzzFeed’s gallery. The first photo shows a group of Christians at a Chicago gay pride parade holding signs apologizing for their church’s homophobia. The second shows a man wearing nothing but underwear hugging the men holding those signs. Those pictures weren’t in NedHardy’s posts. A story about the hug at the gay pride parade had been posted on Reddit, but the post’s title does not include the phrase “faith in humanity.” So how did BuzzFeed find these gems?

After a bit of Googling for phrases like “faith in humanity,” I came upon Andre Bastary’s Pinterest page. Bastary has tagged lots of pictures from around the Web with the phrase “faith in humanity.” Ten weeks ago, he tagged the gay pride photo, rendering it searchable. I’m guessing that’s how it got on BuzzFeed’s radar. It’s hard to say, though, because Shepherd’s post, which links to the sources of some of the photos on its list, doesn’t mention Pinterest or Andre Bastary.

Over the last couple weeks, I have spent many hours and opened hundreds of browser tabs in an effort to reverse-engineer posts I found on BuzzFeed. Recently, the site has expanded beyond its roots as a mere chronicler of memes, hiring a staff of excellent reporters and editors and creating top-notch sections covering politics, technology, and style. I ignored those reported sections. Instead, I spent most of my effort on what the site’s founder Jonah Peretti calls “old-school BuzzFeed”—those meme-saturated listicles that are designed to go viral online. Those posts generate the bulk of BuzzFeed’s traffic, and they are also the way most people get introduced to the site. When I saw a particularly inspired BuzzFeed list—and when the post did not prominently mention its sources—I tried to dig through the Web to find how BuzzFeed produced it.

This wasn’t always easy. BuzzFeed is so popular that its posts often obscure everything else online—for example, if you Google “faith in humanity,” you’ll mostly come up with references to Shepherd’s post, including many sites that pilfered BuzzFeed’s list. NedHardy’s original compilations, meanwhile, have been flushed from the top search results. But I’m a persistent Googler, and I get paid for this sort of thing. With lots of work, I was able to find how the work of others inspired BuzzFeed.

A good example is “14 Mistakes That Really Should Never Have Happened.” This post from last Wednesday shows mindless workplace failures, e.g., cafeteria spoons in a container labeled “forks” and pineapples in a big box labeled “watermelons.” At first glance, the post looks totally original, suggesting BuzzFeed spent a lot of time scouring the Web for images of occupational disasters.

But that’s not what happened. Under each picture in the post, BuzzFeed includes a tiny link to IMGur, a picture-hosting site favored by people on Reddit. There’s something opaque about the way BuzzFeed links to IMGur. BuzzFeed chooses to link directly to the file name of IMGur images. That means when you click on the link, you see only the photo, not the text that the Redditor appended to it. It’s only when you remove the “.jpg” from the URL that you see the full IMGur page for the image. If you do that for all the images in the “14 Mistakes” post, you’ll find that 13 of the images include the phrase “one job” in their titles (as in, “You had only one job to do, and you failed.”)

At that point it becomes obvious how this post came about. Step 1: A BuzzFeed editor noticed a “one job” post on Reddit. Step 2: He searched for the phrase there. Step 3: He found a lot more images. Step 4: He scooped them all up for his own post.

But what about the 14th image, the one that doesn’t use the phrase “one job” in its title? It turns out that was included in a compilation of “one job” images created by Reddit user BarelyMexican. That post, which went up a month ago, received 453,000 views and includes seven of the 14 images BuzzFeed uses. Every one of BuzzFeed’s “one job” images appeared on Reddit first, but neither Reddit nor its users (like BarelyMexican) are credited in the piece.

Once you understand how central Reddit is to BuzzFeed, it’s like spotting the wizard behind the curtain. Whenever you see a popular BuzzFeed post, search Reddit, and all will be revealed. A post called “30 Very Sound Pieces of Advice,” full of photos showing amusing life lessons? You’ll find many of its pictures by searching Reddit for “advice,” “sound advice,” “best advice,” and other such phrases. (You can complete your search by looking at Google Images and IMGur, too.) How about “19 Things That Will Drive Your OCD Self Insane”? Search for phrases involving “OCD.” “Fourteen of the Most Fabulous Animals in the Kingdom”—amazing pictures of animals striking glam poses? Just search the Web for “Bitch, I’m Fabulous,” a well-known Web meme, with particular animals (i.e., here’s a fabulous pigeon, a fabulous gorilla, and a fabulous llama). “Thirty-three Animals Who Are Extremely Disappointed in You”? That mines an old meme, one that’s easy to find all over the Web—including in a BuzzFeed post from last year, “12 Extremely Disappointed Animals.”

On Monday, I talked to Peretti about how BuzzFeed uses Reddit and other online meme havens. He compared the site’s editors to writers on a television show—they’re constantly scouring the Web for ideas, collaboratively discussing those ideas, and then figuring out which of them are worth pursuing. “A lot of what the BuzzFeed editors do is have conversations about the catchphrases or other things people are talking about on 4Chan and message boards and Reddit,” Peretti says. He concedes that some of its ideas have appeared elsewhere online, but he argued that there’s nothing wrong with that because few things on the Web are really original.

“The ‘faith in humanity’ meme has been part of Internet culture for a while,” Peretti says. “Jack had been collecting images for it for a while. He encountered Ned’s site while he was doing this because if you Google ‘faith in humanity,’ it’s one of the ones that comes up. But it wasn’t like that blogger defined this genre—he was doing something similar to Jack.”

Peretti added that even though Shepherd’s post wasn’t the first to document “faith in humanity” pictures, it was unquestionably the best. “In this case we’re popularizers of something that was more widely known in the world of Reddit or 4Chan,” Peretti says. NedHardy’s post includes several blurry images and a few that aren’t easy to figure out. Shepherd removed all those. His list has better, bigger pictures, and he added explanatory captions. “We’re making it into something that will delight and be understandable to the Facebook audience,” Peretti says. “It was almost more what we didn’t include that was the key to that post—we didn’t include inside jokes and memes that most people don’t understand. We took it down to its emotional core and made it more relatable to a general audience. That’s a service we provide, and we’re adding value by doing that.”

This sounded like a pretty good defense to me. But I still wondered why BuzzFeed was so cagey about its sources. Taking other people’s stuff as inspiration is a time-honored practice online. Bloggers do it every day, and most of them acknowledge the original source of whatever they’re writing about. Even posting other people’s pictures without permission, a copyright no-no, has become standard practice on the Web. (BuzzFeed does this often; Peretti has defended it by arguing that because BuzzFeed transforms photos into lists, it is protected under the fair use exception to copyright rules.) Peretti wasn’t hiding the fact that Shepherd spotted the NedHardy post while making his list. Why not at least link to it?

Peretti had no good answer for this. “In cases where it relates to anonymous Internet culture, we don’t have a clear policy” about when to cite your sources, Peretti says. “It’s a moving target—we think a lot about it and try to understand what’s the right way to handle this stuff.”

At the moment, many of BuzzFeed’s editors seem to have their own sourcing policies. Some of them cite Reddit sometimes; others never do. Some of them tell you where they found their images; others almost never do. (Peretti did say that BuzzFeed has a policy not to link to 4Chan because it doesn’t want to steer unsuspecting readers to the graphic horrors found on that freewheeling site.)

I should note that BuzzFeed’s reliance on Reddit doesn’t bother Reddit. Erik Martin, that site’s general manager, told me he doesn’t think BuzzFeed is doing anything wrong. Ordinary Redditors aren’t bothered either. Indeed, they’ll often link to BuzzFeed posts that were inspired by Reddit memes—and those posts are often brimming with appreciative comments.

I did ask Peretti what he thought of it when other sites take content from BuzzFeed. This happens all the time: See the Daily Mail’s rip-off of BuzzFeed’s “34 Pictures That Should Never Have Been Uploaded to the Internet” or Fox Nation’s copying of “35 Photographs of Barack Obama as a Young Man.”

“We see people taking entire posts of ours and publishing them and sometimes linking back and sometimes not linking back,” Peretti says. “My general feeling is that you’ve got to keep your head down and do great work, and sites that do that are never going to be respected. Sites that just look for someone else’s hits—sites that take much more than they add—are never going to be respected.”

I’ll leave it to you to decide if BuzzFeed is taking more than it’s adding. But all ethical issues aside, my exploration into BuzzFeed’s process has left me feeling a bit let down by a site I’ve long loved. It’s still possible to find completely original stuff on BuzzFeed—lists like “The 21 Absolute Worst Things in the World”—that are creative, wonderful, and (as best as I can tell) novel. Most of the time, though, that’s not what BuzzFeed is peddling. The secret to its viral success is to find stuff that’s already a minor viral success and make it better. Repeat the process enough, and you’re bound to get a few mega-hits. That’s not genius. It’s a machine.