It's an insult, an accusation, and a powerful force in modern society.
But what's your defense?
Here is advice on what to look for in a story and in yourself.
The old line goes, "A lie can go halfway round the world while the truth is still putting its shoes on.”
And they didn't know about smartphones.
What someone brands as fake news may be a flat-out lie, a half-truth, a story that depends on anonymous sources or a true story you just don't like.
It doesn't help when people only pay attention to sources they do like.
"That's the big problem we have with the filter bubbles and the echo chambers and people just reading one or viewing one source they're not going to get the big picture," says Dave Cuillier.
"We don't teach civics as much in the schools and there used to be a program that was widespread in our country called Newspapers in Education. So newspapers used to deliver bundles of papers to classrooms and have curriculum and people would learn how news is produced and how to evaluate it critically. That is really rare nowadays."
The fakers know how to hook and reel you in.
Psychologist Dr. Todd Linaman knows emotion, scandal and negativity are powerful bait.
"There's also the confirmation bias that we have as human beings that we read something and see something that seems to confirm a belief and attitude that we have, regardless of the topic we will gravitate toward it, and we are much more susceptible to believe in it."
Fake sites may masquerade as real sites.
A web address that's a little off can help you spot a fake. A CNN imposter site called Breaking-CNN.com said Barbara Bush died a day before she did. At last check, that site was down and for sale. Plenty of people thought the story was from CNN, believed the hoax and helped spread it. They should have wondered why they did not see that sort of story from any other source.
American University created a game that challenges you to identify fake and real news stories. Its’ main lesson is the value of stories that come from reputable sites you can visit to verify a story’s truth and accuracy. A reliable site will quote real people whose identities and connection to a story can be verified. But beware, we found several fake news stories that lifted quotes from real people in real stories and used them to create a twisted version.
This story, from the questionable site The New York Evening claims in a Washington Post opinion piece, former Democratic National Committee Chair John Podesta favored eugenics; a discredited idea embraced by the Nazis and others that advocated selective breeding to improve the human race.
In the real Washington Post article, Podesta did not advocate eugenics but did write in favor of access to birth control as a matter of women’s rights and a way to reduce the impact overpopulation has on the Earth.
In some cases, internet registry sites like WhoIs.com allow you to learn who operates a site and where they are based. WhoIs.com shows The New York Evening is based in Macedonia, a country near Greece that has become notorious as the home of many fake news sites.
The Poynter Institute operates the International Fact Checking Network to help train journalists to check facts more effectively. It offers a thorough but easy to follow cartoon guide to fact-checking, designed by a journalist in Brazil.
Doctor Linaman says to defend against fake news you need to break through your love for your own beliefs and your hate for the other side.
"We've never been more polarized politically in my lifetime that I can recall and because of that, we are more likely to look for information that will incriminate the opposing view. And if we can find it, we're much more likely to use it. The emotional satisfaction we get out of it takes precedence over whether or not it's a good representation of the truth."
And technology makes finding the fakes harder each day.
Buzzfeed recently released a video that seems to be former President Barack Obama saying some insults we won't repeat here.
Then a split screen reveals it's the comedian and filmmaker Jordan Peele imitating Obama’s voice. The video was digitally manipulated to make Obama’s mouth fit Peele’s words.
On a split screen, Obama and Peele seem to say these words together: "You see, I would never say these things, at least not in a public address, but someone else would. Someone, like Jordan Peele. This is a dangerous time. Moving forward we need to be more vigilant with what we trust from the internet. It's a time when we need to rely on trusted news sources."