(CNN) A top trending video on YouTube Wednesday suggested an outspoken survivor of the mass shooting at Marjory Stoneman Douglas High School is an actor.
Calls by student David Hogg for stricter gun laws in the days after last week's massacre have made him the subject of smear campaigns and demonstrably false conspiracy theories.
"I'm not a crisis actor," Hogg told CNN's Anderson Cooper on "AC360" Tuesday. "I'm someone who had to witness this and live through this and I continue to be having to do that."
He added, "I'm not acting on anybody's behalf."
The YouTube video, captioned "DAVID HOGG THE ACTOR," is of a local television report from Southern California in which a young surfer gets into an argument with a Redondo Beach lifeguard after the youth is criticized for placing his boogie board on top of a trash can. It was the No. 1 trending video Wednesday morning until it was taken down following a CNN inquiry.
"We felt threatened," Hogg tells the reporter, speaking of his friend's encounter with the lifeguard. "He seemed unpredictable."
YouTube later removed the video, saying the description on the post violated its policy on "harassment and bullying."
"This video should never have appeared in Trending," YouTube said in a statement. "Because the video contained footage from an authoritative news source, our system misclassified it."
The video-sharing site's statement added: "As soon as we became aware of the video, we removed it from Trending and from YouTube for violating our policies. We are working to improve our systems moving forward."
Still, other videos calling Hogg a crisis actor were still up on the video-sharing site.
Hogg, 17, and many of his classmates have been outspoken about the need for stricter gun laws since they witnessed the massacre of 17 students and staff members at their Florida high school last week.
Memes and other YouTube videos have surfaced with outlandish claims the students are anti-gun "actors" who travel around the country to the sites of mass shootings.
Some have suggested that Hogg's father, a former FBI agent, coached his son to criticize President Donald Trump -- an allegation that Donald Trump Jr. appeared to endorse on Twitter.
It's not the first time such allegations have surfaced. After the 2012 mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, some conspiracy theorists said the massacre was staged by the government and accused victims' families of being paid actors.