On April 20, thousands of students throughout the country participated in National School Walkout Day to help keep the conversation focused on gun reform. There have been 89 school shootings just in 2018, and the one at Marjory Stoneman Douglas High School in Parkland, Florida in February helped create a nationwide movement powered by students to force politicians to make our communities safer. 

The walkouts were scheduled for this specific day because it is the anniversary of the Columbine High School shootings, when two students killed 13 people back in 1999. 19 years later, not much has changed in the way of making sure other devastating shootings don’t happen anywhere, especially in a place like a school. 

Although people of all ages—and people of color in particular—have been advocating for gun reform for many years now, many will agree that the current movement, powered by the students from Parkland, feels different. As president Barack Obama wrote in his TIME entry citing the students leading that movement as one of the most influential people of the year, “By bearing witness to carnage, by asking tough questions and demanding real answers, the Parkland students are shaking us out of our complacency.”

One other important thing to remember about the teenagers of today is that they’ve grown up with social media. That might help to explain why this current movement for gun reform has been so powerful: when they go out to protest, everyone can see it, watch it, and be inspired by it, and that’s by design. 

Below are some of the most powerful posts shared on social media on National School Walkout Day.