Book excerpt: Social media has pitfalls: misinformation, pseudoscience, fraud, and irrational beliefs, presented in an attractive, easy-to-share form. It reinforces your biases by tracking your preferences: it sends only filtered newsfeeds, so that you rarely see anything that might challenge your set notions. Harrison demonstrates how critical thinking can enhance the benefits of social media, while giving readers the skills to guard against its dangers. He also suggests ways to protect yourself against privacy invasion, trolls, and the confusion over fake news versus credible journalism.