"The New Zealand police warned us of a video on Facebook shortly after the live stream began we quickly removed both the Facebook and Instagram accounts of the shooter and the video," Mia Garlick, director of Facebook for Australia and New Zealand, he said in a statement.
Facebook has declined further comments on when the video was removed
What we know
Hours after the attack, however, copies of the creepy video continued to appear on Facebook, YouTube and Twitter , raising new questions about companies' ability to handle malicious content on their platforms.
Facebook "removes any praise or support for the crime and the shooter or shooters as soon as we are aware of it," Garlick said.
The New Zealand police asked social media users to stop sharing the alleged footage and stated that they were trying to make it stop.
CNN is choosing not to publish more information on the video until more details are available.
Technology companies do not consider this priority as a priority
Friday's video rekindles questions about how social media platforms handle offensive content: are companies doing enough to try to capture this kind of content? How fast should they be removed to remove it?
"While Google, YouTube, Facebook and Twitter all say that they are collaborating and acting in the interest of citizens to remove these contents, in reality they are not because they are" I make it possible for these videos to reappear all the time ", has stated Lucinda Creighton, senior consultant of the Counter Extremism Project, an international political organization.
Artificial intelligence tools and Facebook human moderators were apparently unable to detect live streaming of the footage. The company says it was alerted by New Zealand police.
" Technology companies basically don't consider this priority a priority, they twist their hands, they say it's terrible, "he said Creighton. "But what they are not doing is preventing this from reappearing."
John Battersby, a counter-terrorism expert at Massey University in New Zealand, said the country was spared from mass terrorist attacks, partly because of its isolation. Social media has changed it.
"This guy broadcast live footage and his supporters cheered him up, and most of them are not in New Zealand," he said. "Unfortunately, once it's out there and downloaded, it can still be (online)," he added.
The broadcast of the video could inspire the copycats, said CNN analyst Steve Moore, a retired special security agent for the FBI.
"What I would like to say to the public is this: do you want to help terrorists? Because if you do, sharing this video is exactly how you do it," Moore said.
"Do not share the video or be part of this," he added.
Hadas Gold, Donie O & Sullivan, Samuel Burke and Paul Murphy contributed to this report.