Chapter 2 focuses on the benefits side of the cost–benefit analysis equation, and notes that the rise of big data’s predictive algorithms allow law enforcement to measure the likely success rate of their surveillance with far greater precision than in the past. These predictive algorithms have the potential to revolutionize criminal investigations in many ways, by making them cheaper, more accurate, and less biased. However, the surveillance technologies must be designed in ways to ensure that they meet the Fourth Amendment’s requirement of particularized suspicion and to ensure that they do not rely on tainted data.