This article originally appeared in The Last Word on Nothing. Tagline: “Science says the first word on everything, and the last word on nothing”—Victor Hugo.

I am often wrong. I misunderstand; I misremember; I believe things I shouldn’t. I’m overly optimistic about the future quality of Downton Abbey and inexact in my recall of rock-star shenanigans. But I am not often—knock wood—wrong in print, and that’s because, as a journalist, I’ve had advanced training in Bullshit Prevention Protocol.

Lately, as I’ve watched smarter and better-dressed friends believe all manner of Internet nonsense, I’ve come to appreciate my familiarity with BPP. Especially because we’re all publishers now. (Sharing a piece of news with 900 Facebook friends is not talking. It’s publishing.) And publishing bullshit is extremely destructive: It makes it harder for the rest of us to distinguish between bogus news and something real, awful, and urgent.

While BPP is not fail-safe, generations of crotchety, underpaid, truth-loving journalists have found that it dramatically reduces one’s chances of publishing bullshit.

So I believe that everyone should practice BPP before publishing. No prior experience is required: Though it’s possible to spend a lifetime debating the finer points of BPP (and the sorely needed news literacy movement wants high school and college students to spend at least a semester doing so), its general principles, listed in a handy, portable, and free—free!—form here, are simple.

Here’s how they work in practice.

1. Who is telling me this? More specifically, who is writing this and for what publication? How credible is the publication? What are its potential biases? Consider a piece of bullshit that made the Internet rounds earlier this year: The U.K.’s Daily Mail published a striking photo of a sunrise projected on an outdoor screen. The accompanying article, by James Nye, was headlined “China Starts Televising the Sunrise on Giant TV Screens Because Beijing Is So Clouded in Smog.” Let’s say you’re not familiar with the Daily Mail. A quick look at its other headlines (“What Does Your Poo Say About You?” “Man Arrested After Strolling Naked Through Wal-Mart”) will tell you that it can be politely described as a fish-wrapper. Safe to assume, for the purposes of BPP, that it is more interested in Web traffic than accuracy.

2. How does he or she know this? A Google search of James Nye shows that he’s based in Brooklyn. Hmm. So chances are he didn’t see these TV screens firsthand. Yes, there is a photo with the article, but we don’t know where it was taken, what’s happening outside the frame, and if the headline accurately describes what the photo depicts. We’re counting on the reporter to check that, and it doesn’t sound like he was there. (A Google search of Nye also turns up a blog post from the Poynter Institute—a scrupulous news watchdog—that accuses him of fabricating a courtroom scene in a Daily Mail article about a Georgia murder trial.)

3. Given No. 1 and No. 2, is it possible that she or he is wrong? Or lying? Nye is writing for a paper that prizes virality, and he doesn’t appear to have been anywhere near Beijing when he wrote the article. Yes.

4. If answer to No. 3 is “yes,” find another, unrelated source. OK, well, Time and CBS News also picked up this story. Both base their reputation on accuracy, so they have a stake in preserving it—in other words, they’re likely to be more reliable than the Daily Mail. But the Time and CBS posts (now very awkwardly corrected) simply credit the Daily Mail story, without any sign of original reporting. So these are not unrelated sources. They’re essentially the same source as the Daily Mail. Try again.

5. Repeat until answer to No. 3 is “pretty f-ing unlikely.” If you really wanted to know the truth here, you could start by finding the photographer—which might take some doing, since the photo is credited to an agency instead of an individual. But even if he or she confirmed the context of the photograph, you couldn’t count on that—after all, the photographer also has a stake in the story’s popularity and might want to protect it. Better would be to find a friend, or a vouched-for friend of a friend, who lived in Beijing and was willing to take a look at the screens for you. But that person would need to do more than just confirm that the screens existed. He or she would have to confirm that the picture was being shown to citizens because of the smog, meaning the friend would probably have to be comfortable in Mandarin and have enough connections to know who to ask and where to find him or her. Wait. Isn’t this person beginning to sound a lot like a journalist?

Which brings me to my larger point. Preventing bullshit is time-consuming, and thoroughly fact-checking an entire article can feel like a particularly demented form of needlepoint. There’s a good reason why my Facebook posts and tweets are almost exclusively about my family and friends, certain TV shows, and articles written by me and people I know and trust. I don’t have a lot of time to practice BPP for free, and I don’t want to share bullshit.

So you could try to chase down the sunrise-billboard photographer. You could try to find an obliging, knowledgeable acquaintance in Beijing. But you’re probably a busy person, and you probably don’t care all that much about this particular story. So instead, you could sit tight for a couple of news cycles and let a professional journalist check into it—we do still have a few of those, after all. Sure enough, Beijing-based journalist Paul Bischoff, writing for the ethics-conscious pub Tech in Asia, soon reported that the Daily Mail story was a crock. The TV screen in the photo is located in Beijing, but it’s displaying a tourism commercial that includes a rotating series of images. One of which just happens to be a sunrise. Bischoff scolded:

Yes, Beijing is polluted, as we at Tech in Asia have also been critical of, but this story is complete bullshit. International media should be embarrassed for not taking even a moment to second guess the Daily Mail, one of the least reputable news sources in the U.K.

Phew, it’s a good thing BPP kept you from sharing that one, isn’t it?

Thanks for reading, and congratulations. You are now qualified to practice Bullshit Prevention Protocol, and thus to defend truth and justice throughout the Internet. I would tell you that your cape is in the mail. But that would be bullshit.