Algorithms and the artificial intelligence that underlies them make a staggering number of everyday decisions for us, from what products we buy, to how we consume our news, to whom we date, and how we find a job. Making the case that we need to better understand AI, Kartik Hosanagar surveys algorithmic decision-making and reveals their potentially dangerous biases. He also reflects on Microsoft's chatbot Tay, designed to converse on social media like a teenage girl, but instead turning sexist and racist; the fatal accidents of self-driving cars; and our frustrating experiences on services like Netflix and Amazon.