A colorful assortment of international tradespeople, drug-pushers, swindlers, and fraudsters, spammers have become a familiar feature of our digital landscape. Finn Brunton’s investigation of the question of spam, Spam: A Shadow History of the Internet — the problems of defining it, understanding it, and tackling it — takes us to the front of an ongoing and highly sophisticated technological war, a keenly contested territorial struggle for control of the information superhighway.