The spread of fake news (FN) has attracted attention from disciplines ranging from social sciences to Artificial Intelligence. This work is novel because it explores the news-sharing behaviour of social-media users, focussing on those that spread FN, rather than the psychological motivations behind them. The 14-item Risky News-Sharing Quotient (RNSQ) was developed and Exploratory Factor Analysis discovered three relevant factors: (i) news-sharing behaviour that contributes to debunking FN; (ii) news-sharing frequency and attitudes to sharing; and (iii) news-sharing behaviour that contributes to the spread of FN. The study, conducted among university students, found that 75% reported risky news-sharing behaviour that spreads FN. No link was found between perceiving FN as a problem and debunking it. Moreover, 83% of survey participants were unable to identify a FN story. Overall, the findings suggest an inability to apply knowledge of the relevant FN detection strategies to debunk FN, but importantly an apparent lack of motivation to check the veracity of a news story. From these conclusions, better-informed educational intervention strategies can be implemented to address the FN problem in-situ, such as promoting the importance of responsible news-sharing by raising awareness of how the spread of FN can impede the proper functioning of societies.