Speaking at the Cannes Film Festival, where she is promoting her new film The Dead Don't Die, the 26-year-old said: "I think our world is going through a lot obviously.
"But for my generation specifically, social media has been terrible."
She claimed many young people were unaware of important news issues.
"It's a useful platform but it does scare me when you see young boys and girls not really aware of the news going on," she added.
"It's selfish - I don't wanna say selfish, that's rude - but it's dangerous for sure."