Yolanda Renee King is nine years old. Her grandfather - Martin Luther King Jr - was the leader of a civil rights movement that changed America forever. He was shot and killed almost exactly 50 years ago. On Saturday, she stood in front of a crowd of 800,000 people in Washington, DC, and paraphrased his most famous words: "I have a dream that enough is enough, and that this should be a gun-free world." She was the youngest speaker at the March for Our Lives rally in Washington, but not by much. Naomi Wadler, 11, said she spoke for African-American girls who had been killed by guns. Most other speakers were teenagers who had lost loved ones, including several students from Marjory Stoneman Douglas High School in Florida - where a school shooting took 17 lives on February 14. It is these students who organised the march and founded the #NeverAgain movement for stronger gun control laws. Ever since an former student entered their school and opened fire, they have been tweeting, organising and making their voices heard. "We are going to be the last mass shooting," said 18-year-old Emma Gonzalez in a speech just days after it happened. She spoke again on Saturday, listing the names of the 17 victims and then standing in silence until six minutes and 20 seconds had passed. That, she explained, was how long it took the shooter to kill them. For the most part, the students have been showered in praise and media attention. Five of them appeared on the cover of Time under the headline "Enough". They have met celebrities, received a handwritten letter of the support from the Obamas and raised millions of dollars for their cause. "Spread the word," chanted King on Saturday, leading the crowds with her. "Have you heard? all across the nation we are going to be a great generation." Some have compared the movement to the 1960s, when thousands of students protested against racism and the Vietnam War. Is another, similar era of youthful influence beginning? Yes, say some. As Wadler said, "My friends and I... have seven short years until we too have the right to vote". Young people know that they are the future, and they're determined to change it. They are also extremely media savvy; they can use social media, videos and interviews to build support for a movement in just a month. Grown-ups, beware. Young people may be leading the chants, point out others, but unlike the 1960s, people of all ages are chanting with them. "It has to be one of the least anti-establishment social movements in American history," observed Emily Witt in The New Yorker. Yet the real power still lies with the politicians in charge; and they do not seem to be listening.