Policies geared toward eliminating financial rewards for producing bogus news.

On Monday, the top trending story if you searched Google for "final election vote count 2016" was a fake story on a site called 70News claiming that Donald Trump had won the popular vote, even though he had not. And in the week before the election, Facebook and Google were being criticized about fake news on their sites, which critics believe could have swayed the presidential race's outcome.

Google responded Monday with a pledge to restrict fake news sites from using its AdSense advertising network. Facebook, for its part, updated its policy to clearly state that its advertising ban on deceptive or misleading content applied to fake news.

"We do not integrate or display ads in apps or sites containing content that is illegal, misleading or deceptive, which includes fake news," Facebook said in a statement. And Facebook chief Mark Zuckerberg on Saturday tried to put the kibosh on the idea that Facebook's platform influenced the election.

"Of all the content on Facebook, more than 99 percent of what people see is authentic. Only a very small amount is fake news and hoaxes," Zuckerberg said. "The hoaxes that do exist are not limited to one partisan view, or even to politics. Overall, this makes it extremely unlikely hoaxes changed the outcome of this election in one direction or the other."

Still, Google and Facebook are not preventing fake news or hoaxes from appearing on the social networking site or in Google search. Instead, the companies' policies are geared toward trying to reduce the financial incentive for producing fake news. And for Google, it's not just about seeking the truth. Advertisers don't want their wares displayed next to bogus content.

"Moving forward, we will restrict ad serving on pages that misrepresent, misstate, or conceal information about the publisher, the publisher's content, or the primary purpose of the web property," Google said in a statement. Google also has the same policy for pornography or violent content. AdSense vets content with artificial intelligence and humans to ensure compliance.

For its part, Facebook has been hit hard by some who accused the social-media platform of tilting voters in favor of Trump by allowing completely fabricated stories, including one that Trump won the endorsement of Pope Francis, to circulate on the site.

The Pew Research Center, meanwhile, in May said that 62 percent of Americans obtain some, or all, of their news on social media—the bulk of it from Facebook.