“Children are dying.” “I will fight every single day.” “I just want to speak.” “We call B.S.” These students survived a shooting at their school. Now they’re leading a national movement for stricter gun control. Just days after the shooting, they called for school walkouts around the country, traveled to the Florida State Capitol — “You failed us” — and planned a nationwide march. Some of them can’t even vote yet. It’s clear these students are doing things differently. Here’s how. #NeverAgain is leveraging social networks to mobilize faster than most movements before it, according to experts who study the rise of social and political movements. One week after the shooting, the #NeverAgain Twitter handle is verified and has more than 81,000 followers. In just a few days, student leaders have crowdsourced more than $3 million through online campaigns and celebrity donations. They’re also handling their own crisis control by directly responding to critics. “I lost a best friend who was practically a brother, and I’m here to use my voice because I know he can’t.” These survivors are presenting their personal stories of loss as part of their fight, converting grief into power by getting in the face of adults. “So, Senator Rubio, can you tell me right now that you will not accept a single donation from the N.R.A. in the future?” The #NeverAgain movement wasn’t formed in a vacuum. It’s riding on the most recent wave of youth activism, which picked up speed around 2010. Student protests ebbed after the antiwar movement of the ’60s and ’70s. “We are fed up.” Young people today are getting involved to change systemic inequalities they were raised to believe had already been taken care of. The Dreamers, students against sexual assault, Occupy Wall Street, and the Black Lives Matter movement all had strong involvement by college-educated millennials. These groups have had modest success. President Barack Obama made sure campuses did more to investigate cases of sexual assault. And he later protected Dreamers from deportation. “You can come out of the shadows and get right with the law.” It’s too early to tell if the #NeverAgain movement will sustain the momentum it needs to bring tangible change. But it’s an election year, so politicians might find their demands difficult to ignore.