Maybe it's author Michael "Fire and Fury" Wolff hinting that President Donald Trump is having an affair with United Nations Ambassador Nikki Haley.

Maybe it's the waves of lies from Russian hackers that have flooded major social-media sites, causing global confusion and chaos.

Maybe it's rumors that Pope Francis has a brain tumor or that he's preparing for a Third Vatican Council, one sure to split the Church of Rome.

Whatever "fake news" is, the pope's World Communications Day message made it clear that he believes Satan is behind it all, whether journalists and mass-media leaders know it or not.

"We need to unmask what could be called the 'snake-tactics' used by those who disguise themselves in order to strike at any time and place," wrote the pope. "This was the strategy employed by the 'crafty serpent' in the Book of Genesis, who, at the dawn of humanity, created the first fake news, which began the tragic history of human sin."

The pope released this text on Jan. 24, the feast of St. Francis de Sales -- the patron saint of journalists -- even though World Communications Day will be on May 13. The "fake news" hook is in the title: " 'The truth will set you free.' Fake news and journalism for peace."

The problem is that few people -- especially in culture-wars America -- agree on what "fake news" means. It's hard to imagine a more partisan term, when President Donald Trump shouts it at a rally. Meanwhile, many journalists have downplayed Gallup polls showing that public trust in the news media is lower than ever.

Concerning the crucial definition issue, Pope Francis wrote: "It refers to the spreading of disinformation online or in the traditional media. It has to do with false information based on non-existent or distorted data meant to deceive and manipulate the reader. Spreading fake news can serve to advance specific goals, influence political decisions, and serve economic interests.

"The effectiveness of fake news is primarily due to its ability to mimic real news. ... It grasps people's attention by appealing to stereotypes and common social prejudices, and exploiting instantaneous emotions like anxiety, contempt, anger and frustration."

Fake news can, in social-media networks, spread so fast that "authoritative denials" fail to contain the damage, said Francis.

Part of the problem, however, is that consumers now distrust many authoritative voices in journalism and the government, noted veteran New York City journalist Clemente Lisi, one of my faculty colleagues at The King's College in lower Manhattan.

"If Dante were around today, he would certainly add a circle in hell that includes journalists for the way many people perceive that we twist facts and purposely disseminate misinformation to millions upon millions of people each day," he argued, in an essay for The Media Project.

Some journalists are part of the problem, but others carry on doing accurate, balanced reporting. Lots of fake information flows through social media channels, but many proposals to fact-check and control these public forums are frightening, in terms of their implications for free speech. Would the public trust their new protectors?

Once again, what is fake news? Yes, it's rumors, acidic political fairy tales and outright hoaxes. But can the fake-news label be pinned on screwed-up, mistake-plagued news about current events? What about biased, advocacy journalism -- whether in talk-TV shouting matches or elite newspaper headlines? Are politicos accurate whenever they yell, "fake news," when facing information they don't like and want to see suppressed?

The bottom line, argued Lisi, is clear: "Fake news is a real problem, but the devil really is in the details when it comes to who's really to blame."

For example, "unmasking" fake news can be hard, argued the pope, because so many news consumers are only paying attention to news sources that reaffirm what they already believe. They never encounter voices and information that "could effectively challenge prejudices and generate constructive dialogue."

Thus, news consumers -- using social media -- can easily turn into "unwilling accomplices in spreading biased and baseless ideas," he said.

"The tragedy of disinformation is that it discredits others, presenting them as enemies, to the point of demonizing them. ... Fake news is a sign of intolerant and hypersensitive attitudes, and leads only to the spread of arrogance and hatred."