Student Sophie Sandberg has been going around New York writing out unwanted catcalls on pavements.
The 21-year-old says she's trying to raise awareness about sexual harassment in the city.
Women send her the unwanted comments said to them and then Sophie goes to the place where it happened and writes it out in big letters in chalk.
Sophie told Newsbeat she hopes her work will make people think twice about catcalling.
"When I started doing the project I realised people get really aggressive and vulgar comments.
"When it first happened to me, it sounded like a compliment, like 'Hey beautiful' and 'Hey sexy'.
"I felt so uncomfortable. It sounded like a compliment but I felt like I was being watched and my body wasn't mine. I was only 15."
Sophie, who started the project in 2016, takes photos of the catcalls written on the pavement and posts them on Instagram.
She has so far posted 102 pictures and has more than 5,000 followers.
"I thought chalk would be the easiest. It's colourful and bright and it's washable, so it is not vandalism," she says.
Sophie says the recent "Me Too" movement is a great example of people starting to speak out against unwanted sexual advances.
"People haven't been talking about sexual harassment in the work place and now they are, it feels like an avalanche.
"If others share their stories it makes you want to come forward with your story too."
Sophie says she hopes her project will spread to other cities across the world.
"That's one of my goals. I've been contacted by people in Canada and Texas, which is good."
The student hopes the project will encourage people to step in next time they witness street harassment.
"Writing it in the same place that it happened, I hope the person who said the words may remember and think 'Oh those were my words'."