Kelly Ripa and Anderson Cooper co-hosted last night's screening of "Bully" with the Weinstein Company, the Cinema Society and Bing.

Celebs from Russell Simmons (in trademark Yankees cap, clutching a plastic bottle filled with healthful-looking green juice), Michelle Trachtenberg, and Carson Kressley to David LaChapelle, Andre Leon Talley and Rachel Roy turned out in droves for a Crosby Street Hotel screening of the hotly anticipated Lee Hirsch-directed documentary “Bully.”

Hosted by The Weinstein Company and Bing with Anderson Cooper and Kelly Ripa, the screening left a powerful impression on many in the all-star audience. Sitting in the safe space of a boutique hotel’s screening room, dressed to the nines while watching kids in the heartland suffer for the very uniqueness that might make them popular in a place like New York, was a bit jarring.

The film follows five families in Georgia, Oklahoma, Mississippi and Iowa — three with children who have been victimized by persistent bullying, and two who have lost children to suicide. (The 110-minute film opens with heartbreaking footage of one of the teen suicides as a baby, establishing an emotional intensity that never eases.)

In remarks to the audience, which also included Caroline Murphy, Heather Matarazzo, Gossip Girl’s Kaylee DeFer, Teen Vogue’s Andrew Bevan, Harvey Weinstein, and Cinema Society founder Andrew Saffir, Cooper warned, “Bullying today is not like when I was a kid. It used to be that it only happened in schools. The home was a respite.”

“Now, because of social media, kids are bullied around the clock.”

Cooper underscored one of the film’s main themes, the infuriatingly inadequate response of overwhelmed school officials like Kim Lockwood, assistant principal of East Middle School in Sioux City, Iowa, where much of the film takes place. (In one grim scene, Lockwood — who comes to personify being part of the problem if you’re not part of the solution — relentlessly badgers a bullying victim for his reluctance to accept his tormentor’s obviously forced apology: “You’re just like him!” The distraught youth has the clarity to retort, through clenched teeth: “I don’t hurt people.”)

Kelly Ripa’s involvement with the film began when Cooper invited her to a town hall meeting at Rutgers after the suicide of Tyler Clementi. Like Cooper, she blames social media for intensifying the bullying plague: “It’s TV, it’s iChat, it’s Twitter,” Ripa told Velvet Roper. “Kids don’t need to be tweeting… they don’t need phones, computers. Computers should be for homework and that’s it!” Ripa’s own children, age 9, 10 and 14, are well protected — in theory: “We only have one computer in the house, and it’s great — it’s in the kitchen! They resent us for it, but I don’t care,” Ripa laughed.

The marketing of “Bully” resembles an advocacy campaign more than a Hollywood rollout. The documentary’s naturalistic profanity earned an R rating from the MPAA — “which we totally think sucks,” lamented director Hirsch — preventing it from being screened in the schools where the filmmakers think it is most urgently needed. (A petition to change the rating to PG-13, launched by a Michigan teen, has drawn nearly 300,000 signatures at Change.org.)

Hirsch, who was bullied as a youth, draws no line between his artistry and his activism. (The Oklahoma father of an 11-year-old suicide victim is shown campaigning against bulling on Facebook, and organizing a series of “Stand For The Silent” rallies that bring together several of the families.) “We have a real opportunity with this movie to change hearts and minds,” Hirsch told the crowd. “Schools may have programs, but if there’s a culture that says we’re not going to deal with it, that athletics and buildings are more important…”