In the 2005 case Illinois v. Caballes, the U.S. Supreme Court declared that "the use of a well-trained narcotics-detection dog…during a lawful traffic stop generally does not implicate legitimate privacy interests." The upshot od that police can get permission from a dog to rifle an innocent man's belongings. How did canines acquire this authority? As Senior Editor Jacob Sullum explains in the cover story from Reason's March issue, credulous courts have been mesmerized by the superhuman olfactory talents of police dogs. Yet this dog license is hard to square with the Fourth Amendment, Sullum writes, unless it is reasonable to trust every officer's unsubstantiated claim about how an animal of undetermined reliability reacted to a person, a suitcase, a car, or a house.