Sofia Coppola's Bling Ring brings wannabe famous five to Edinburgh Film Festival

It's more than just a tale of daylight robbery, however. "It's about middle-class suburban kids wanting to be part of this life they think is glamorous, which is being promoted in our culture today," says Sofia Coppola, the writer-director who turned their story into her new film, The Bling Ring, after reading Vanity Fair account, The Suspects Wore Louboutins. "They talked about being a celebrity and having status brands and not really about doing some work [to achieve that]."

We meet at the Cannes Film Festival, just a few minutes after Coppola's cast has been enjoying a glam photo shoot at the Carlton Hotel. It's the day after the premiere, which inadvertently generated one of the biggest news stories of the festival when more than $1m worth of Chopard jewellery was stolen from a nearby hotel safe during The Bling Ring gala screening ("It wasn't us, that's for sure!" jokes Israel Broussard, one of Coppola's young stars, later).

While Coppola's cast is largely fresh-faced newcomers (with the exception of Harry Potter star Emma Watson), the real Bling Ring are, like, way more famous. Sisters Alexis and Gabby Neiers, for example, both were featured on a reality television series, Pretty Wild, cataloguing their excessive party lifestyle. And in the ultimate irony, Alexis Neiers, during her final days in jail, was residing in a cell adjacent to one occupied by actress Lindsay Lohan, one of the Bling Ring's victims.

After reading transcripts from both journalists and police officers, Coppola met with some of the real Bling Ring, including Nick Prugo – the only male in the group – but she claims this wasn't her focus. "The real kids? I'm not so concerned about those five kids," she says. "It's more useful to talk to a larger audience. They went to jail but I'm not so concerned with them. Particularly, it was this idea of where our culture is going that is important to look at."

If anything Coppola's film is a damning indictment of today's celebrity-obsessed society – driven by social media and reality television. With sites such as Twitter, "We're so close to these celebrities," says Broussard, who plays Marc, the character modelled on Prugo. "And these kids took it to the next level. They did what everybody else wanted to do, but didn't know exactly how. And when I say that, I mean they became Paris Hilton, Lindsay Lohan and Audrina Patridge – at least for an hour!"

His director concurs, wondering "how this instant information might be affecting young people". Quiet and softly-spoken, dressed today in a pale blue blouse with thick white cuffs and lapels, Coppola is almost the antithesis to these youngsters (even if she has occasionally fed the beast herself, shooting the odd Christian Dior commercial). Growing up, she didn't idolise celebrities. "There are people I admire but I didn't have that obsession. I liked bands and stuff but I wasn't crazy about it."

Yet Coppola saw celebrity from the inside – whether it was with older actor-cousin Nicolas Cage or her own father, famed film director Francis Ford Coppola, who cast her when she was 18 as Mary Corleone in The Godfather Part III. While critics savaged her performance, it didn't turn her away from Hollywood. By 1999, she directed her first feature, The Virgin Suicides, a year after making her first short Lick The Star which, like her debut and The Bling Ring, revolved around cliques.

Since then, Coppola's work has touched on celebrity regularly – from Bill Murray's jaded star in 2003's Lost In Translation (which won Coppola a Best Original Screenplay Oscar) to Stephen Dorff's Chateau Marmont-dwelling actor in 2010's Somewhere. In between, Kirsten Dunst played the title role in 2006's Marie Antoinette – surely the biggest celebrity of the 18th century. Whatever her fascination with the subject, she insists it's a by-product of her work. "Fame isn't something I'd want to pursue."

Based in Paris, away from LA, and married to French musician Thomas Mars, with whom she has two young daughters, Romy and Cosima, Coppola admits The Bling Ring came out of being a mother. "I'm looking at it more as a parent," she says. So is she worried how her daughters will be affected by this world? "I'm not worried about them turning into those kids but I am aware of trying to protect them- from being aware of what they are watching and exposed to."

Whatever Coppola's reasoning and whatever the social implications of her film, she's certainly assembled it in an assured manner. "She's a crime boss, the way she directs," says Broussard, referring to the stealthy, in-the-shadows way she gets what she wants. Before the shoot started, the group's rehearsals consisted of "scheduled bonding" – which included a "fake" robbery of a house belonging to one of Coppola's friends.

Katie Chang – who plays Rebecca, based on real Bling Ring-leader Rachel Lee – remembers being sent an "intense" email, addressed to her character. "[It said], 'Rebecca, you have a mission – you've been tasked with breaking into Rachel Bilson's home.'" One of the real victims, actress Bilson (best known for The OC) was robbed between three and six times during April and May of 2009, with more than $130,000 worth of goods stolen.

Driven to the house, "We all hopped out of the van and put our hoods on and climbed the fence," recalls Chang. "Taissa [Farmiga, who plays fellow Bling Ring-er Sam] found an open window and we climbed in, and we were all trying to be really sneaky and heist-y. Then Taissa was like 'You know what? I'm just going to the fridge! You guys can go find the clothes. I'm just going to eat.' And we all started laughing. That's when it hit all of us: these kids weren't necessarily trying to pull off a huge heist. They were just having fun."

That may be true – though doubtless Bilson and co didn't find it so amusing to be robbed. Orlando Bloom, another victim, was coincidentally in Cannes for his new movie Zulu. So how did he feel about a film being made on this topic? "If my house hadn't been one of the houses hit, I'd think 'Yeah, that'd be an interesting story to turn into a movie' – because it is!" he says. Coppola even asked him to do a cameo but he declined. "I just said it was too close to home to want to be involved in."

One celebrity who did want to be involved – a move that rather sums up her own hunger for fame – was Paris Hilton. The main victim of the crimes, not only does she make a brief cameo in the film, but she lent her real-life mansion to the production. So gaudy it has to be seen to be believed, it comes complete with a dancefloor room (complete with stripper pole) and pillows with her own face on. "We didn't art-direct that; that's the way she lives," says Coppola.

Unquestionably, it lends the film a queasy air of authenticity. "When we got in there and started shooting, we were just digging around Paris Hilton's closet!" says a gleeful Broussard. Yet isn't it telling that Hilton and the world she represents came to Cannes to be seen on the red carpet for this film? "I don't want to make big statements about Paris Hilton," says Coppola. "I know that it's surprising that she's here but I'm glad that she's supporting it."

What's more, is it hypocrisy that a film condemning our obsession with celebrity and designer labels saw the cast troupe up the Cannes red carpet in Louis Vuitton, Chanel and Dior? Chang, while admitting she appreciates the irony, thinks not.

"We're enamoured by all these beautiful clothes, but none of us really expected any of this to happen. Whereas these kids, it was a complete desire and want." A sense of warped entitlement to a lifestyle they'd not earned? "Absolutely. It was this real childish idea of 'finders keepers'." And perhaps a desire to cover up a gaping black hole in their own lives.

The Bling Ring (15) screens at the Edinburgh International Film Festival on June 22 and June 23, and goes on general release on July 5.