Read the full article at The Guardian.

The lies multiplied so rapidly Cori Langdon could hardly keep up. The taxi driver’s cellphone video of the Las Vegas mass shooting was being widely republished by conspiracy theorists, who were using it as “proof” that the massacre was staged by the government and that Langdon was an “actor”.

Langdon thought that if YouTube and Facebook removed some of the content, the online attacks and bogus stories might stop spreading. But it wasn’t so simple.

When some footage was taken down, conspiracy theorists saw it as further evidence that Langdon was involved in a cover-up. Some told her they were worried the FBI had gotten to her.

“It just fuels them even more,” said Langdon, who was harassed online even while being hailed by some as a hero for picking up passengers at the Mandalay Bay shooting that killed 58 people in October. “These conspiracy theorists love their guns. They are freaked out and paranoid.”

Concerns about conspiracy theorists bullying victims of mass shootings have escalated this month as student survivors of a Florida high school massacre have become vocal proponents for gun reforms, making them prime targets for online abuse. Google and Facebook have faced particularly intense scrutiny for their role in spreading false stories claiming teenage survivors are so-called crisis actors hired to promote gun control.

“You’re motivated to attack information that is not consistent with your beliefs. This is just a human trait,” said Colleen Seifert, a University of Michigan psychology professor, adding that when pro-gun conspiracy videos are suddenly removed, viewers can become further entrenched in their beliefs. “Absence of information might feed conspiracy arguments, because there’s no explanation for the disappearance.”