The prevalence of fake news has increased with the recent rise of social media, especially the Facebook News Feed, and this misinformation is gradually seeping into the mainstream media. Several factors have been implicated in the spread of fake news, such as political polarisation, post-truth politics, motivated reasoning, confirmation bias, and social media algorithms.

Fake news can reduce the impact of real news by competing with it. For example, a BuzzFeed News analysis found that the top fake news stories about the 2016 U.S. presidential election received more engagement on Facebook than top stories from major media outlets.

It also particularly has the potential to undermine trust in serious media coverage. The term has at times been used to cast doubt upon credible news, and former U.S. president Donald Trump has been credited with popularising the term by using it to describe any negative press coverage of himself. It has been increasingly criticised, due in part to Trump's misuse, with the British government deciding to avoid the term, as it is "poorly-defined" and "conflates a variety of false information, from genuine error through to foreign interference".