Speaking at the Cannes Film Festival yesterday, Watson said the impact of social media on the current generation was a "shame", as director Coppola suggested many teenagers would now do anything for notoriety.
"The whole story seemed to say so much about our time and growing up with Facebook and Twitter," Coppola said. "This could never have happened 10 years ago.
"I was thinking about how these kids (in the film) must be affected by all of that, and how reality TV seems so normal now to all of them having grown up with it. The idea of no privacy has become the norm."
Of the true story, which she read about in a magazine, she said: "I think their quotes really struck me: how they didn't seem to think they had done anything wrong, and how they were mostly interested in the fame the robberies had brought them."
The Bling Ring sees Watson's self-obsessed character Nikki dressing up in little more than underwear and pole dancing in Paris Hilton's house.
She has now disclosed she researched the role by watching reality television including The Hills, Paris Hilton and the Kardashians.
"It's fun to explore a different side of yourself through a character. It gave me permission to do loads of crazy stuff."
