But the woman in Harlem was right: it is illegal. Because a stoop can be viewed from the street or sidewalk, it can be considered a public place, which is defined by the New York Administrative Code as “a place to which the public or a substantial group of persons has access.” A gate can provide a divide between these public and private spheres, but not always. Some drinkers edge a few steps closer to the front door, even though that doesn’t make a difference: more than a few have been fined when the passing parade happened to include a police officer.

Yet night after night, the illegality continues.

On the corner of Cumberland Street and DeKalb Avenue in Fort Greene, a couple newly relocated from Montreal prepared an elaborate spread of mozzarella salad, a cutting board filled with pata negra and other cured meats, accompanied by a Spanish red wine. On 105th Street and Riverside Drive in Manhattan, a 20-something couple sipped Bacardi Coconut on the rocks through straws from tall white foam cups. At the corner of West Fourth and West 12th Streets in Manhattan, a woman whose mother had been in intensive care for two days smoked American Spirits while sitting with her two Chihuahuas on the steps leading up to a red-brick building, an orange cup of Red Stripe at her feet.

At about 9:30 p.m. on a Sunday in south Park Slope, Brooklyn, three couples sat on low-slung beach chairs and on the stairs of a brownstone with small glasses of Writers Tears whiskey or cans of Coors Light. One woman ducked inside briefly to make sure her child was still asleep.

Although it is unclear how many summonses are handed out to people drinking on their stoops, in 2011 the New York Police Department issued 124,498 of them for public drinking, which is not a crime but does constitute a “quality of life” violation. It is at the discretion of the patrolling officer whether or not to write up the pink slip, which usually carries a $25 fine and a trip to criminal court, or both. But more important, it requires being caught in the act.