Gun owners in America are being encouraged to hand in or destroy their military-style assault rifles.
Using the hashtag #OneLess, one man said he wanted to ensure the weapon "will never be able to take a life".
Scott Pappalardo posted a video of himself cutting up his AR-15 rifle, which has been viewed more than 15 million times.
His decision follows the latest deadly school shooting, which saw seventeen people murdered in Florida last week.
President Donald Trump has been criticised for blaming the attack on the mental health of the suspect, and refusing to tighten gun control laws.
In his video, Pappalardo said that "Quite frankly any legal gun owner is capable of snapping and committing a horrific crime, even without mental illness," he said.
"I've decided today, I'm going to make sure this weapon will never be able to take a life.
"The barrel of this gun will never be pointed at someone", he said.