's sarah frier looks at the fake news hits of the year and what social media companies can do to contain sarah: 2017 is the year that we realized how quick and easy spreading misinformation on social media is, and how profitable the spread of fake news can be. before the u.s. presidential election, fake news was a get rich quick scheme to cash in on online advertising, but this year we learned it is also a tool to disrupt democracy. the kremlin-backed internet research agency reached over 150 million americans on facebook with inflammatory posts intended to stir conflicts over issues like race and religion. this is done with 80,000 posts million americans on facebook boosted by $100,000 in ad spending. >> these ads are just the tip of a very large iceberg. sarah: and it resulted in google, facebook, and twitter all testifying in hours of congressional hearings about russia's tactics and how to try to stop them. but it is not limited to the u.s. the spread of fake news became a global issue in 2017. france and germany successfully fighting it in their own election. meantime, other governm