With its low coffee prices, plentiful tables and available bathrooms, McDonald’s restaurants all over the country, and even all over the world, have been adopted by a cost-conscious set as a coffeehouse for the people, a sort of everyman’s Starbucks.

Behind the Golden Arches, older people seeking company, schoolchildren putting off homework time and homeless people escaping the cold have transformed the banquettes into headquarters for the kind of laid-back socializing once carried out on a park bench or brownstone stoop.

But patrons have also brought the mores of cafe culture, where often a single purchase is permission to camp out with a laptop. Increasingly, they seem to linger over McCafe Lattes, sometimes spending a lot of time but little money in outlets of this chain, which rose to prominence on a very different business model: food that is always fast. And so restaurant managers and franchise owners are often frustrated by these, their most loyal customers. Such regulars hurt business, some say, and leave little room for other customers. Tensions can sometimes erupt.

In the past month, those tensions came to a boil in New York City. When management at a McDonald’s in Flushing, Queens, called the police on a group of older Koreans, prompting outrage at the company’s perceived rudeness, calls for a worldwide boycott and a truce mediated by a local politician, it became a famous case of a struggle that happens daily at McDonald’s outlets in the city and beyond.