Untruths about Tuesday's elections overwhelmed local election officials, who said they were dealing with "tsunamis of misinformation," lost sleep and worked extra long hours.
The officials told us they were dealing with several common types of election-related misinformation. So we decided to pursue three categories of the rumors they encountered using CrowdTangle, Facebook's own analytics tool, and then focused on spreading one of the lies in each of the categories. We also recorded the amount of tweets about the rumors we followed using BuzzSumo, another analytics tool.
The data showed how a single rumor spreading a false narrative can quickly resonate on Facebook and Twitter, generating tens of thousands of shares and comments. This has made misinformation particularly difficult for election officials to combat.
"The real cost of misinformation is not borne by platform companies," said Joan Donovan, director of research at Harvard University's Shorenstein Center. "You are paid by everyone else who has to deal with the consequences."
A Facebook spokesperson Andy Stone said it banned voter interference, worked with fact-checking organizations, and had established a voter intelligence hub with accurate information.
Twitter said it didn't create specific Twitter moments explaining these particular rumors, but rather aims to proactively debunk false allegations and provide information about the vote via email.
We found the following:
1. Ballot crop false claims
This misinformation shows the unproven claim that ballot papers are "harvested" or collected by unauthorized persons and given in bulk.
In the example we focused on, Representative Ilhan Omar, a Democrat from Minnesota, was falsely accused last month of being involved in or related to systematic illegal voting.
According to our analysis, there were 3,959 public Facebook posts that shared this rumor. These posts generated 953,032 likes, comments and shares. Those who shared the lie included two pro-Trump Facebook groups targeting Minnesota residents and President Trump himself. At least 26,300 tweets also discussed the lie.
Jeremy Slevin, a spokesman for Ms. Omar, said in a statement emailed that the claim was not true.
2. False claims by mAll ballot papers are dumped or shredded
Mail-in ballot papers and related material thrown was another popular lie that election officials said they heard. We looked at one of those rumors spread by a far-right website called The Right Scoop. This month, the website posted an article entitled "Tons of Trump Mail-In Ballot Motions SHREDDED on the Back of a Truck Heading for Pennsylvania".
The article generated 163 individual public posts on Facebook. According to our analysis, it has been liked, commented and shared 91,000 times on the social network. It was also shared on Twitter 1,032 times.
Politifact debunked the video on which the article was based. Facebook added a label to posts that shared rumors that it contained false information.
The Right Scoop later corrected his post – but his correction didn't go as far as a lie and only received a single one like on Facebook. The Right Scoop did not respond to a request for comment.
3. False claims by Antifa and Black Lives Matter protesters about planned violence at polling stations
Election officials also said people presented them with false claims that Antifa, the loose gathering of left wing activists and Black Lives Matter protesters coordinated rioting at polling stations across the country.
One of those rumors started this month when The Federalist, a conservative company, noticed a liberal activist website called Shut Down DC said people should protest on the streets if Mr Trump is re-elected. Right-wing commentators added flammable captions to their posts sharing the federalist's article. Many said it was evidence of planned violence by the left on election day and after, and stated without evidence that Black Lives Matter was involved.
The false rumor was then shared in 472 public Facebook posts according to our analysis. 99,336 likes, shares and comments were generated. The rumor was shared at least 400 times on Twitter.
Craig Sawyer, a right-wing commentator and Marine veteran, shared the rumor on Facebook October 16. In an email, he said his post was not a call to violence and that the New York Times should focus on "the main planners and financiers of all riots, arson, looting and murders" instead.