What is fake news? Well, unlike satirical sites such as The Poke and The Onion, which don't fall into this category, fake news websites intentionally publish fraudulent, hoax or factually inaccurate news stories. They will also plagiarise legitimate news stories from other sites, but change the headlines to something more sensationalist in order to draw in readers.
Further to Facebook's testing of new reporting options for fake news (see below), it is now actively marking disputed stories in the U.S. German users were first to get the ability to report posts as fake news, with the update seemingly being prioritised because of the upcoming German elections and the fact that fake news stories about Angela Merkel were circulating. We're yet to see a disputed story in the UK, so if you spot one, let us know. This is what they look like:
Where is this fake news?
As well as being found in internet searches (including Google News and Google AMP stories), you will also find them on social networks including Facebook (normal posts and Facebook Instant Articles) and Twitter.
The links -- either from a search engine or found in a Facebook post or tweet on Twitter -- direct readers to the website in question.
Many fake stories focus on politics (and not just U.S. politics) but also on health, well-being and religion. Fake 'news' are also used as propaganda. As long as people are interested and click through to the story, that's all that matters.
Why do fake news sites exist?
Most fake news sites are based in Macedonia, Romania, and Russia but they are also based in the U.S. and other countries. The reason they exist is to make money.
That's true for most websites, but with fake news sites, the money is made on the back of deceit, clickbait, and plagiarism.
By writing sensational headlines based on popular current affairs -- most recently the U.S. presidential election -- these sites receive a lot of traffic and therefore earn -- relatively speaking -- a lot of money from the adverts displayed on them.
According to BuzzFeed, which researched many of the Macedonian sites, the teenagers running them can earn enough money to buy pretty much whatever they want. One teenager publishing pro-Trump stories was reportedly earning $5,000 per month from his site, and up to $3,000 per day when a story was shared a lot on Facebook.
How to tell what's real and what's fake
One recent example of fake news was the story which claimed Donald Trump had won the popular vote. It was hosted on a WordPress blog, which looked unprofessional if you viewed it on a desktop PC by browsing directly to the site.
The problem was that the article ended up at the top of Google's search results, which meant a lot of people read and shared it. Plus, readers using smartphones wouldn't necessarily have noticed that it wasn't a reputable site, nor that it was - indeed - fake news.
Fake news is made harder to discern when stories are picked up and converted into a more easily readable format, which is what Google AMP and Facebook Instant articles do. It's the same with Apple's News app, too.
They all take a news story and reformat it to remove all the clutter (and adverts) that you'd find on the original website's page.
From the reader's perspective, this is great because the article loads quickly and looks good. But it also lends the same benefits to fake news stories, which means it can be very hard to spot that something is fake. The clues are only in what is being said, and the potential for bad grammar and misspellings. Not everyone will pick up on these, of course.
What is being done to stop fake news
Google and Facebook have already said that they will stop serving ads on fake news sites.
Things came to a head after Facebook and Twitter, in particular, were blamed for influencing the outcome of the US election by allowing fake news to spread on their networks.
Fake news sites have to request approval for their site before any ads will appear, but Google has said it is updating its AdSense program to prevent ads being placed on sites distributing fake news.
With no ads, and therefore no money, those running the sites will have no incentive to continue.
Facebook has moved to ban fake news sites from advertising on the social network.
Google is yet to announce that it's doing anything about preventing fake news stories appearing in search results, but Facebook has outlined how it is tackling the problem. Adam Mosseri, VP of Facebook's News Feed said, "It's important to us that the stories you see on Facebook are authentic and meaningful. We're excited about this progress, but we know there's more to be done. We're going to keep working on this problem for as long as it takes to get it right."
Facebook is rolling out a couple of new reporting options - as a test - to see how they help. If you see a story you suspect is fake news, you can report is as a suspected fake news article and mark it as fake or send the person who posted it (or shared it) informing them you think it is fake.
There's also a new system where Facebook will use feedback from the site's users to send stories to third-party fact-checking organisations. If they say a story is fake, it will be flagged as such in your news feed, and may be shown lower down than other stories. You'll also get a warning if you try to share the story:
What is Pizzagate?
Fake news is not always harmless. Recently, a man walked into Comet Ping Pong -- a pizza restaurant in Washington, D.C. -- and fired a rifle. Dubbed, Pizzagate, the event came about because of fake stories that the pizzeria was a home for a child sex abuse ring that included Hilary Clinton and John Podesta.
These fake stories have been circulating on the web and social networks for months, but although they have already been proven baseless and false, the conspiracy theories haven't gone away. The man who fired the rifle and refused to leave the premises until he was satisfied that there were no children being kept captive said he went there to "self-investigate" the stories.