"This study examines racism, antisemitism, and xenophobia on Facebook and Twitter. The authors were looking for patterns in the mass of posts, tweets, and images that circulate on social media. To do this, they focused on a series of case studies. These demonstrate that political discussion on social media is often dominated by angry and loud voices who too often seem to press the 'send button' before thinking of the consequences, or, in some cases, deliberately aim to sow discord and division." (Foreword)