  In this study, we closely look at the use of social media contents as source
or reference in the U.S. news media. Specifically, we examine about 60 thousand
news articles published within the 5 years period of 2013-2017 by 153 U.S.
media outlets and analyze use of social media content as source compared to
other sources. We designed a social media source extraction algorithm and
investigated the extent and nature of social media source usage across
different news topics. Our results show that uses of social media content in
news almost doubled in five years. Unreliable media outlets rely on social
media more than the mainstream media. Both mainstream and unreliable sites
prefer Twitter to Facebook as a source of information.
