It’s not always easy. No one, and perhaps particularly a teenage girl, would like to have their looks and mannerisms mocked online. But for Thunberg, it’s a daily reality. “I have to think carefully about everything I do, everything I say, what I’m wearing even, what I’m eating—everything!” she tells TIME during a train ride to Hamburg, Germany, last spring. “Everything I say will reach other people, so I need to think two steps ahead.” Sitting next to her father, she scrolls past hateful comments—the head of a Swedish sportswear chain appeared to be mocking her Asperger’s—then shrugs them off. So many people have made death threats against her family that she is now often protected by police when she travels. But for the most part, she sees the global backlash as evidence that the climate strikers have hit a nerve. “I think that it’s a good sign actually,” she says. “Because that shows we are actually making a difference and they see us as a threat.”