Police sniffer dogs are widely trusted, but research suggests they are less accurate and more harmful than courts assume. They produce many false alerts, and they respond to unconscious cues from handlers, including racial biases. In Canada, police generally need 'reasonable and probable grounds' to search a home or a car, but in cases such as R. v. Kang-Brown and R. v. Chehil the Supreme Court allowed dog sniffs on the lower standard of 'reasonable suspicion', because they were seen as highly accurate and minimally intrusive. The new research argues that both assumptions no longer hold.

In 1909 D. W. Griffith made a 14-minute film about a speculator who corners the wheat market and doubles the price of bread. A farmer sows his field while a 'Wheat King' gambles in the Chicago wheat pit; bakers raise the loaf from five cents to ten and the poor line up for bread. Griffith cut back and forth between the farm, the feast and the breadline, a technique called parallel editing, so audiences saw both ends of the economy at once. The film drew on Frank Norris's stories and on a real scheme: months earlier Chicago financier James Patten had cornered wheat, sent bread prices up and made about $5 million, roughly $185 million today.