Casey Sherman, centre, 17, lead student coordinator for the Parkland march, speaks during a planning meeting with Marjory Stoneman Douglas High School students, parents and volunteers in a hotel meeting room in Coral Springs, Fla. Picture: AP Photo/Wilfredo Lee

Washington - As they've stepped out of the hallways of Marjory Stoneman Douglas High School and into the national spotlight, the Parkland, Florida, teenagers have become Twitter influencers, TV news show mainstays and the stoic-faced subjects of a Time magazine cover.

But they've also increasingly become targets: Their most prominent critics are people who see them less as survivors of a tragedy and more as pawns in a larger effort to influence gun policy.

The latest attack came from Colion Noir, a host on NRA TV who took to the airwaves on the eve of the Parkland teens-led March on Washington, telling them: "No one would know your names" if a student gunman hadn't stormed into their school and killed three staff members and 14 students.

"To all the kids from Parkland getting ready to use your First Amendment to attack everyone else's Second Amendment at your march on Saturday, I wish a hero like Blaine Gaskill had been at Marjory Douglas High School last month because your classmates would still be alive and no one would know your names, because the media would have completely and utterly ignored your story, the way they ignored his," Noir said.

Colion Noir is a pseudonym for Collins Iyare Idehen Jr., a lawyer and gun rights activist from Houston who has nearly 650 000 subscribers on YouTube. The man he references, St. Mary's County Sheriff's Deputy Blaine Gaskill, is the 34-year-old SWAT-trained officer who engaged a teenager who opened fire at Great Mills High School in southern Maryland. Noir and others have said Gaskill's intervention illustrates that the solution to school gun violence is more "good guys with guns."

Noir did not return messages from The Washington Post seeking comment.

Noir is the latest of a growing number of people who've criticised the teens. An aide to a Florida legislator was fired after he called the school shooting survivors crisis actors who travel from tragic place to tragic place making impassioned but bogus political pleas to take away gun rights. Donald Trump Jr. liked a tweet saying one of the most vocal students had been coached by his FBI-agent father to peddle "anti-Trump rhetoric and anti-gun legislation."

And several people have criticised the teens for smiling on the set of CBS's morning news show, saying the students were "posing for the photos like they are partying rock stars."

But Noir accuses the teens of being downright un-American in creating a march he says is designed to promote stripping others of their Second Amendment rights.

"They're running Season 5 of their gun-control reality show, featuring the freshest cast of characters yet in their modern march on Washington - except this time for less freedom," he said. "These kids ought to be marching against their own hypocritical belief structure."

In the video, he also inaccurately claims that American media has ignored Gaskill's hero story, and other stories that run counter to the gun-control narrative.

Gaskill's story has been featured on several mainstream media outlets, including The Washington Post. CNN called it "an example of what a school resource officer is supposed to do in such a circumstance." The New York Post ran a story with the headline "This is the officer who stopped the Maryland school shooter."

The Parkland activists haven't responded to Noir's comments directly, though they have gone on the offensive against people who've peddled conspiracy theories and otherwise tried to discredit them.

"I just think it's a testament to the sick immaturity and broken state of our government when these people feel the need to peddle conspiracy theories about people that were in a school shooting where 17 people died, and it just makes me sick," David Hogg told BuzzFeed News. "It's immature, rude and inhuman for these people to destroy the people trying to prevent the death of the future of America because they won't."