Facebook is full of fake news stories. On Election Day, don’t fall for them.

A public service announcement from your friends here at Vox: There will be an enormous amount of false information on Facebook, the internet, and TV this Election Day. Do yourself (and the country) a favor and ignore it.

Politicians have always played fast and loose with the truth, cable news networks have always gotten stories wrong, and the internet has always been a place for conspiracy theories and misleading stories and photos.

But the 2016 campaign has seen an unprecedented increase in the sheer number of false news stories being shared on Facebook or posted to genuine-looking but entirely fake news sites run by tech-savvy young people looking to make some money off this long and bitter election.

Take the Denver Guardian, which earlier this month ran a story with the attention-grabbing headline “FBI AGENT SUSPECTED IN HILLARY EMAIL LEAKS FOUND DEAD IN APPARENT MURDER-SUICIDE.” The article ricocheted across Facebook and gained tens of thousands of shares despite the fact that there is no such thing as the “Denver Guardian” and that the “story” in question is a complete fabrication.

It’s a dynamic that deeply concerns President Barack Obama, arguably the savviest user of social media in American political history — and the politician who has been targeted in the majority of Facebook’s most paranoid, conspiracy-minded, and outright racist viral posts.

“As long as it’s on Facebook…people start believing it,” he said during a campaign stop in Ann Arbor, Michigan, on Monday. “It creates this dust cloud of nonsense.”

To make matters even dicier, many current and former US officials believe that Russia may try to deliberately spread false information on Election Day to make would-be Hillary Clinton voters stay home or simply to shake overall confidence in the American political system.

All of which means that if you see or read something on Election Day that appears too dramatic to be true, there’s probably a good and simple reason: It isn’t.

In November 2012, Fox News aired a video clip showing a member of the Black Panthers standing outside a polling station in Philadelphia. It was a single person at a single polling station in a heavily black, heavily Democratic area, but Fox anchors strongly suggested that it was part of a broader pattern of voter intimidation by militants determined to stop then-GOP nominee Mitt Romney. The segment was rebroadcast frequently throughout the day.

Flash-forward four years. It’s certainly possible that Fox News — or a left-leaning station like MSNBC — will find a similar type of clip and present it in a way that is deliberately misleading.

Amazingly, though, that could literally be the least of our problems. A much bigger concern is the proliferation of entirely fake news sites with entirely fake stories, often operated by tech-savvy entrepreneurs living overseas.

A BuzzFeed article earlier this month found that young people in the Macedonian town of Veles (population 45,000) had created more than 140 pro-Trump news sites running posts every day that “are aggregated, or completely plagiarized, from fringe and right-wing sites in the US.”

To take one example from the story, a website called ConservativeState posted an article with the headline “Hillary Clinton In 2013: ‘I Would Like to See People Like Donald Trump Run for Office; They’re Honest and Can’t Be Bought.’”

The story was a complete fabrication, but it immediately went viral, racking up more than 480,000 shares, reactions, and comments on Facebook in less than a week. By contrast, BuzzFeed noted that the New York Times bombshell revealing that Trump had declared a $916 million loss on his 1995 income tax returns drew a comparatively small 175,000 Facebook interactions over an entire month.

That kind of traffic is lucrative business for the Macedonians, some of whom told BuzzFeed that they made up to $5,000 per month pushing information they knew to be untrue.

“Yes, the info in the blogs is bad, false, and misleading,” one of these youngsters told BuzzFeed. “But the rationale is that ‘if it gets the people to click on it and engage, then use it.’”

Trump is also getting a boost from paid trolls in Russia who pretend to be American on multiple social media accounts that they use to make pro-Trump comments on traditional publications like the New York Times as well as on Facebook and Twitter. The lies and false information often gets parroted by both conservative news outlets like Fox News and Trump himself.

“Are Russian trolls to blame for that?” a female troll asked comedian Samantha Bee. “Maybe people are to blame too. They’re lazy and believe everything they read.”

The bitter race between Clinton and Trump may end up being the kind of excruciatingly close race where small pockets of voters in key states ultimately decide our next president. That makes dirty tricks like recent ads wrongly telling Clinton supporters that they could vote by text all the more dangerous.

As the Washington Post reported, the fake ads circulated on Twitter with the exact fonts and imagery used in real Clinton campaign materials. They told Clinton backers that they could “save time” and “vote from home” by texting her name to a five-digit phone number. One English-language ad read, “Vote early. Text ‘Hillary’ to 59925.” Another was written entirely in Spanish.

They were lies, of course. You can vote by mail or in person, but you most definitely cannot do it by texting Clinton’s first name to a random phone number. It’s unclear how many would-be Clinton voters fell into the trap, or who specifically was responsible for setting it. But in a race where every vote matters, the fake ads could easily have real impact.

And that’s the biggest thing to keep in mind on Election Day. Facebook’s enormous reach means that lies and distortions — regardless of whether they come from GOP dirty tricksters, partisan journalists, paid trolls in Russia, or money-seeking entrepreneurs in Macedonia — can genuinely impact the outcome of the campaign. Be careful with what you read, be careful with what you retweet, and be careful with what you share on Facebook. There are bad actors out there hoping to mess with our election. Don’t make it easier for them.