Many are “architectural jewels, that capture the soul of cinema,” she said. But to salvage the theaters, she said, “We have to work on bringing people back into the cinema.”

The students did not know much about cinema when they stormed the theater, Mr. Carocci said.

But the movement has changed that. Now, some of the students have gone to film school. Others have dipped their toes in the business.

A group of two dozen — today from 16 to 25 years old — has organized the summer outdoor cinema, a two-month program of films ranging from Disney movies to experimental documentaries to horror films (shown at midnight every Saturday, with headphones to avoid disturbing the neighbors).

They have been given the keys to another abandoned Trastevere cinema that they hope will inject fresh energies into the neighborhood’s movie scene.

The final film shown in the outdoor cinema this year was Gianni Di Gregorio’s sweet comedy, “Pranzo di Ferragosto,” or “Mid-August Lunch,” which was coincidentally set in Trastevere, and included a local actor or two.

“You’ve done something marvelous,” the director told the organizers and spectators before the screening of the film. “The youth of the Cinema America are doing something important. Not just for Trastevere but for Rome and for Italy.”