claim that media bias is propagated down from the management and that individual journalists are relatively neutral in their work. In What Liberal Media? The Truth About Bias and the News (2003), Eric Alterman also disputes the belief in liberal media bias, and suggests that over-correcting for this belief resulted in the opposite. Censorship of conservative content Tech companies and social media sites have been accused of censorship by some conservative groups, although there is little or no evidence to support these claims. At least one conservative theme, that of climate change denialism, is over-represented in the media, and some scientists have argued that media outlets have not done enough to combat false information. In November 2013, Nathan Allen, a PhD chemist and moderator on Reddit's science forum published an op-ed that argued that newspaper editors should refrain from publishing articles from people who deny the scientific consensus on climate change. Conservatives have argued that Facebook and Twitter temporarily limiting the spread of the Hunter Biden laptop controversy on their platforms, even though parts of the story later turned out to be accurate, "proves Big Tech's bias". Shadow banning Claims of shadow banning of conservative social media accounts (manipulating algorithms to minimise the exposure and spread of specific content) were brought to the fore in 2016 when conservative news sites lashed out after a report from an unnamed Facebook employee on May 7 alleged that contractors for the social media giant were told to minimize links to their sites in its "trending news" column. The Nieman Foundation for Journalism at Harvard investigated and found no evidence of shadow-banning of conservatives. Fact checking and fake news Conservative outlets like The Weekly Standard and Big Government have criticized fact checking of conservative content as a perceived liberal attempt to control discourse. A 2019 study found that fake news sharing was less common than perceived, and that actual consumption of fake news was limited. Another 2019 study found that older, more conservative people were more likely to have shared fake news during the 2016 election season than moderates, younger adults, or "super liberals". An Oxford study has shown that deliberate use of fake news in the U.S. is primarily associated with the hard right. According to a 2019 study of fake news on Twitter during the 2016 election season, 80% of "all content from suspect sources was shared by less than 1 percent