The power and proliferation of fake online news stems not only from its apparent ubiquity but also from a sense of the presence of others that social media sites create, according to new research conducted by Gita Johar, the Meyer Feldberg Professor of Business at Columbia Business School, along with doctoral students Rachel Meng and Youjung Jun. The researchers found that when people are presented with claims whose veracity is ambiguous they are less likely to fact-check the claims when the information is consumed in a group setting.