(CNN) — It’s time for a new rule on the web: Double, no, triple check before you share. Especially if it seems too good to be true.

Why? Look no further than Donald Trump’s Twitter account. Trump claimed Sunday morning that “Twitter, Google and Facebook are burying the FBI criminal investigation of Clinton.”

Not only was there no proof of this, but it was pretty easy to disprove. The FBI email inquiry was at the top of Google News; FBI director James Comey’s name was at the top of Facebook’s “trending” box; and Twitter’s “moments” section had a prominent story about the controversy.

Nevertheless, Trump’s wrong-headed “burying” claim was his most popular tweet of the day. About 25,000 accounts retweeted it and almost 50,000 “liked” it, helping the falsehood spread far and wide.

The rise of social media has had many upsides, but one downside has been the spread of misinformation. Fake news has become a plague on the Web, especially on social networks like Facebook. As I said on Sunday’s “Reliable Sources” on CNN, unreliable sources about this election have become too numerous to count.

So that’s what I recommended a “triple check before you share” rule.

New web sites designed to trick and mislead people seem to pop up every single day. For their creators, the incentives are clear: more social shares mean more page views mean more ad dollars.

But the B.S. stories hurt the people who read and share them over and over again. Many of these fakes reinforce the views of conservative or liberal voters and insulate them from the truth. The stories prey on people who want to believe the worst about the opposition.

A recent BuzzFeed study of “hyperpartisan Facebook pages” found that these pages “are consistently feeding their millions of followers false or misleading information.”

The less truthful the content, the more frequently it was shared — which does not bode well for the nation’s news literacy during a long, bitter election season.

“Right-wing pages were more prone to sharing false or misleading information than left-wing pages,” the BuzzFeed reporting team said.

On a few occasions, made-up or highly misleading stories have even snuck into Facebook’s “trending” box — a problem that the company says it is trying to address.

In a few cases, Trump aides and family members have themselves been duped by fake news stories, including a hoax version of ABC News with a story headlined “Donald Trump Protester Speaks Out: ‘I Was Paid $3,500 To Protest Trump’s Rally.'”

A close look at the web site reveals that it is not, in fact, the actual ABC News. But the site tricked Trump’s son Eric Trump in early October. “Finally, the truth comes out,” he tweeted, promoting a link to the bogus story.

As soon as I spoke about this on television on Sunday, CNN detractors filled my inbox with messages saying that CNN is the ultimate example of “fake news.”

But that’s a deliberate attempt to confuse the issue. Whatever faults CNN has, news organizations small and large try very hard to report the truth.

Fake news sites and Facebook feeds, on the other hand, traffic in misinformation. My sense is that there are three buckets of these sites:

1, Hoax sites with totally made-up news headlines that try to trick you;

2, Hyperpartisan sites that aren’t lying, per se, but are misleading, because they only share good news about your political party and bad news about the other party;

3, “Hybrids” that purposely mix a little bit of fact and then a lot of fiction.

These sites aren’t going away, so it’s up to Internet users to spot fake news and avoid spreading it.

Fact-checking sites like Snopes can help — they are devoted to ferreting out hoaxes and tricks.

Josh Stearns, a longtime media activist who now works at Democracy Fund, said newsrooms also have a role to play.

“Fact checking has taken center stage in this election, but newsrooms need to go beyond fact checking politicians statements and help debunk viral misinformation too,” he told me. “At a time when trust in media is at an all time low, journalists should call out these fake news stories and help citizens tell fact from fiction.”

Trump’s false claim about Google, Facebook and Twitter “burying” bad news about Clinton criticized what he called the “very dishonest media.” Ironically, he was using Twitter to blast Twitter.

Trump may have gotten the idea from an inaccurate Zero Hedge blog post alleging a “social media blackout.” The blog post contained false information. I asked the Trump campaign to provide a source for the wild claim, but no one has responded.

NEW YORK (CNNMoney) — When Philando Castile was shot by a Minnesota police officer Wednesday evening, his girlfriend’s first instinct was to start broadcasting.

Her choice to live-stream the aftermath of the shooting on Facebook Live spurred immediate national news coverage of Castile’s death.

By Thursday morning, it was the top story on television and across the web.

Live streaming enabled the woman, identified on Facebook as Lavish Reynolds, to share the incident even more quickly than a recorded cellphone video could have.

And it provided an even more intimate, distressing view of the shooting.

Reynolds’ first words to her audience were “Stay with me.” She panned over to Castile, whose white shirt was covered in blood, then brought the camera back to her face, capturing her shock up close.

One of her viewers wrote a comment: “Don’t stop recording.”

Reynolds also documented her interactions with the authorities. The live stream, however, does not show what occurred before or during the shooting.

Facebook Live automatically records live streams and lets people re-watch them later. Reynolds’ video was spotted quickly and shared by Black Lives Matter activists.

By the end of the night, other live streams showed mourners and protesters gathering outside the Minnesota governor’s mansion.

Meanwhile, on Facebook, Reynolds’ recording was temporarily pulled from her page. It may have been flagged by users or by Facebook’s computers as being graphic.

The video’s disappearance disturbed some users. Facebook restored it within hours.

“We’re very sorry that the video was temporarily inaccessible. It was down due to a technical glitch and restored as soon as we were able to investigate,” a Facebook spokesperson told VentureBeat and other news outlets.

Now the video is accompanied by a warning that it is graphic. “Are you sure you want to see this?” the label asks, requiring users to consent before viewing it.

According to Facebook’s measurement tool, it has been viewed 2.5 million times on Reynolds’ page. And by now it has also been seen countless millions more times on television.

Ever since the rise of “citizen journalism” in the mid-2000s, analysts have commented on the empowering capabilities of smartphones and other easily portable cameras.

Live-streaming is the newest form of citizen journalism — and the most immediate form yet.

But there have been several well-documented instances of crimes being live-streamed on Facebook Live, posing a quandary for the company.

Related: Facebook struggles to stop crimes from being live streamed

In June, for example, an Islamic extremist who killed a police commander and his romantic partner in France posted a 12-minute video on Facebook while holding a hostage.

But for every twisted, criminal use of live streaming, there are dozens of stories about how the services are beneficial.

Most often they’re used for prosaic purposes — broadcasting birthday parties and weddings and day-to-day activities. Newsworthy moments are being captured all the time, too.

Facebook Live and a rival streaming service, Twitter’s Periscope app, were recently used by Democrats in the House of Representatives to live-stream the sit-in they staged to protest lack of movement on gun control legislation after television cameras in the chamber were turned off.

(CNN) — Melissa Harris-Perry will not be back on MSNBC.

On Sunday morning, two days after the host’s private fight with management went public, an MSNBC spokesman confirmed that the channel is “parting ways” with her.

Earlier in the morning, Harris-Perry posted a photo on Twitter and said “Farewell #Nerdland,” a nickname for her weekend show, “Melissa Harris-Perry.”

“Inviting diverse new voices to table was a privilege,” she tweeted. “Grateful for years of support and criticism.”

Harris-Perry confirmed to CNNMoney that her representatives are in talks with MSNBC about an exit deal.

Harris-Perry had felt for months like MSNBC was trying to squeeze her off the air and take away her editorial point of view.

On Friday, she spoke out about the treatment, saying she had been “silenced” by MSNBC and placed in a form of cable news purgatory, having been pre-empted for two weekends in a row.

“Our show was taken — without comment or discussion or notice — in the midst of an election season,” she wrote in a letter to staff that was shared with her fans.

MSNBC and its rivals are all trying to squeeze higher ratings out of the chaotic primary season. The channel pre-empted her for campaign coverage with a “Place for Politics” title.

The same thing has happened to other shows, too, MSNBC said in a statement responding to her letter on Friday. The channel called her reaction “surprising, confusing and disappointing.”

But Harris-Perry said the February pre-emptions were merely the most visible manifestation of the channel’s marginalization of her show.

In the letter, she said “no one on the third floor,” where MSNBC’s executives work at 30 Rockefeller Center, “has even returned an email, called me, or initiated or responded to any communication of any kind from me for nearly a month.”

She also pointedly noted a “dramatic change” in the “editorial tone and racial composition of MSNBC’s on-air coverage.”

Harris-Perry’s MSNBC contract expires in October.

“All negotiations are occurring with third parties,” Harris-Perry said in a statement to CNNMoney on Sunday morning. “I am not personally in direct communication with anyone employed with MSNBC.”

She added, “The goal of the negotiation at this point is to determine the terms of severance, not reconciliation.”

(CNN) — Dr. Ben Carson’s path to the White House begins by walking away from Fox News.

On Friday, amid media reports about Carson’s preparations to possibly run for president, Carson and Fox confirmed that his relationship with the cable news channel had been severed.

From now on, when Carson appears on Fox, it’ll be as a newsmaking guest, not as a paid contributor.

Carson, formerly a neurosurgeon at Johns Hopkins Hospital, signed up with Fox back in October 2013. Earlier that year, he had garnered attention for speeches at the National Prayer Breakfast, the Conservative Political Action Conference and elsewhere.

While contributing to Fox programs, he openly flirted with the possibility of a presidential run in 2016. In September, he told the radio host Hugh Hewitt that the chances of a run were “reasonably good,” but that he was waiting for a “few more months.”

It’s been a couple of months, at least. Earlier this week, The Washington Times (which publishes columns by Carson) reported that a flattering documentary about him, titled “A Breath of Fresh Air: A New Prescription for America,” is set to air this weekend in local markets across the country.

“A production company run by conservative personality Armstrong Williams filmed the documentary and is paying for the airtime,” The Times reported. “Mr. Williams is also Mr. Carson’s business manager.”

Soon after the hourlong ad telecasts were reported, Fox said Carson was no longer a contributor. Fox took similar action with two contributors, Newt Gingrich and Rick Santorum, in the run-up to the 2012 election.

Carson said in a statement Friday evening that “at this time, no decision has been made to run for president.”

“However, recognizing the possibility, Fox News felt I needed complete independence to fully examine my options,” he said. “My departure has been thoroughly amicable and is in the best interest for both Fox News and myself.”

Fox’s own website quoted a GOP strategist, Tyler Harber, as saying, “The man’s running. He’s been running for two years.”

The-CNN-Wire

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