A North Korean defense minister is executed with anti-aircraft fire for falling asleep in a meeting (or was it a parade)? If you don’t find that hard to believe, you probably buy everything you see advertised on TV.

Even so, news media throughout the world repeated this story about the alleged demise of General Hyon Yong Chol, based on an anonymous report from South Korea’s National Intelligence Service.

Although the NIS later backtracked, saying Hyon had been "purged" but not necessarily executed, much less in such a gruesome manner, more such stories will circulate and find an eager audience -- and not just about North Korea. They’re also likely to have longer legs than the subsequent denials, because the Internet audience is little different from that of old-style TV and newspapers: It still selects news and opinion consistent with its attitudes and beliefs.

People are more likely to share a news story when it chimes with their worldview, or with that of popular network users they follow. Selective exposure, as the phenomenon is known in academic circles, is a source of joy for propagandists and intelligence services that seek not so much to convert people to their views as to reinforce the core beliefs of their respective audiences.

North Korea, as a secretive dictatorship with media resources limited to a few toothless propaganda sites, is a particularly easy target. Its current leader, Kim Jong Un, is apparently tougher on the country’s ruling elite than his father Kim Jong Il and his grandfather Kim Il Sung used to be. In a recent article for the Moscow Carnegie Center, North Korea expert Andrei Lankov wrote that of the seven top officials who stood next to Kim Jong Il’s coffin at his funeral, six have since "disappeared without a trace." One was arrested during a government meeting and his execution was reported in North Korea. Another simply lost his post and was edited out of official photographs. Make no mistake: The North Korean regime is not run by liberal softies.

Still, the most gruesome tales of the youngest Kim’s brutality have turned out to be hoaxes. No, he did not execute former lover Hyon Song Wol for making porn movies. And no, he didn’t feed his uncle Jang Song Thaek to 120 hungry dogs.

It has never been proven that North Korea used mortars or flamethrowers to execute people, for the simple reason that no one willing to talk to the media has ever been present at a North Korean execution. The blurry satellite images used as proof of North Korean executions by anti-aircraft guns should strike a familiar chord with anyone who has been closely watching the conflict in eastern Ukraine: There, such pictures and out-of-context videos have been used daily by each side to accuse the other of unspeakable brutality, including the downing of the Malaysian passenger jet, in which 298 people died.

Many of these watchers draw conclusions from photographs juxtaposed with Google Maps satellite images, the provenance of which is all but impossible to verify: Who put them on the Internet and why? Every time such findings make the news, there’s an answering salvo using similar material. Much of this kind of analysis is simply grist for people who already have an established view of what happened.

Did Russian President Vladimir Putin really snap a pencil during last February’s tense cease-fire talks in Minsk? No he didn’t, but Ukrainians and their Western sympathizers were primed to believe it when someone posted a doctored image from the pool footage online.

Did former U.S. State Department spokeswoman Jen Psaki really say: "There are no Ukrainian refugees in Russia. Those are tourists. In the Rostov Mountains, there is wonderfully healing air"? No she didn’t, but Putin fans like to think she’s too ignorant to know the Rostov region has no mountains and too stubborn to admit that hundreds of thousands of Ukrainians have fled to Russia since the conflict started.

The list goes on. In the case of the Russian-Ukrainian conflict, the falsehoods are described as part of a "hybrid war." North Korea’s case shouldn’t be treated any differently. It’s hard to say who benefits the most from the stories of flamethrowers, anti-aircraft guns and hungry dogs: South Korean conservatives and intelligence operatives, who want to portray North Korea as a version of hell; Western governments that need Kim as a bogeyman; or Kim himself, who doesn’t mind being feared as long as he isn’t mocked.

“You know what’s more destructive than a nuclear bomb? Words,” a fictional Kim says in the recent Hollywood comedy "The Interview," blamed for bringing on the recent Sony hack. It’s not quite certain that North Korean hackers perpetrated that crime, but again, pinning it on them benefits everyone. Sony gets some sympathy as a victim of government-sponsored terrorism; U.S. intelligence is seen doing its job, tracking down cybercriminals; and even North Korea gets some grudging respect for pulling off the biggest computer attack in history.

If North Koreans have really learned computer warfare, expect them to pick up the media skills of Russian and Ukrainian propagandists soon. No doubt North Korean spin doctors would glamorize Kim’s corruption fighters and portray his brutal regime as one of the last bastions against pervasive U.S. spying; it worked for China.

And what if Kim has already mastered the game and all the gory rumors originate from his covert propaganda machine? If that’s impossible to believe, maybe selective exposure is playing its tricks on you, too.