Facebook, YouTube Blindsided by Mosque Shooter’s Live Video

Social media platforms including Facebook Inc. are facing harsher scrutiny after a shooter accused of killing 49 people in two mosques in New Zealand appeared to livestream the murders over the internet.

While platforms including Twitter and YouTube said they moved fast to remove the content, users reported it was still widely available hours after being first uploaded to the alleged shooter’s Facebook account. The video, which shows a first-person view of the killings in Christchurch, New Zealand, was readily accessible during and after the attack—as was the suspect’s hate-filled manifesto.

Armed police maintain a presence outside the Masjid Ayesha in Manurewa on March 15.

Photographer: Phil Walter/Getty Images

Facebook, YouTube and other social-media platforms are struggling ...