Many critics of the presidential election are partly blaming false information and fake news stories propagated on Google and Facebook for influencing the outcome. While some Facebook employees share this concern, Facebook CEO Mark Zuckerberg has largely dismissed the notion that fake news on Facebook contributed to Trump’s victory.

Despite this, both Google and Facebook have now taken steps to address the challenge of false news. Google is implementing a policy change that bars sites displaying fake news from using ads from the Google Display Network. This is an attempt to cut off their potential revenues.

Accordingly, Google issued the following statement:

We’ve been working on an update to our publisher policies and will start prohibiting Google ads from being placed on misrepresentative content, just as we disallow misrepresentation in our ads policies. 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.

Facebook also updated its Facebook Audience Network terms to prohibit sites that feature illegal or deceptive content (fake news) from using its ads.

According to various reports, much of the fake news circulated during the election was generated in Macedonia. Many of these sites were using the Google Display Network to monetize. Presumably, this will no longer be the case after today.

While Google and Facebook are the two largest ad platforms, there are alternatives. It’s also far from clear that these measures will sufficiently address the underlying problem. These policy changes don’t directly address the issue of fake news showing up in the Facebook News Feed or ranking in Google search results.

Now that the election is over, it’s likely that the dissemination of fake news will die down for the time being. And while automation can probably flag most of the deceptive content, without some sort of human editorial review or intervention, it will be effectively impossible to completely stamp out fake news.