https://www.cnbc.com/2019/03/18/facebook-youtube-worked-to-remove-copied-new-zealand-shooting-videos.html

In the hours after a shooting suspect in New Zealand broadcast his rampage of a mosque across social media, internet companies worked quickly to remove versions of the video that continued to pop up on their platforms.

Facebook said Saturday it removed 1.5 million videos of the attack in the first 24 hours after it was originally livestreamed. Facebook said 1.2 million of those videos "were blocked at upload." Facebook did not immediately respond to CNBC's inquiry about the number of people who viewed the videos of the attack prior to their removal.