Google and Facebook have announced measures aimed at halting the spread of "fake news" on the internet by targeting how some purveyors of phoney content make money: advertising.
Google says it is working on a policy change to prevent websites that misrepresent content from using its AdSense advertising network, while Facebook updated its advertising policies to spell out that its ban on deceptive and misleading content applies to fake news.
The shifts comes as Google, Facebook and Twitter face a backlash over the role they played in the US presidential election by allowing the spread of false and often malicious information that might have swayed voters toward Republican candidate Donald Trump.
The issue has provoked a fierce debate within Facebook especially, with Chief Executive Mark Zuckerberg insisting twice in recent days that the site had no role in influencing the election.