This Essay takes seriously the relevance of law enforcement effectiveness and the role of empiricism in understanding the constitutionality of the police practices at issue in the Floyd case and urban police practices more generally; it also recasts the debate a bit. A critical but obscured issue is the mismatch between the level of analysis at which the Supreme Court articulated the relevant test for constitutional justification of a stop-and-frisk in Terry v Ohio and the scale at which police today (and historically) engage in stop-and-frisk as a practice. To put this more succinctly, while the Court in Terry authorized police intervention in an individual incident—when the police officer possesses probable cause to believe that an armed individual is involved in a crime—in reality, stop-and-frisk typically is carried out by a police force en masse as a program. Although the constitutional framework is based on a one-off investigative incident, many of those who are stopped—the majority of them young men of color—do not experience the stops as one-off incidents. They experience them as a program to police them as a group, which is, of course, the reality. That is exactly what police agencies are doing. Fourth Amendment reasonableness must take this fact into account. I make an argument here about how we should approach this issue.