 "Christchurch shooting")
The Friday massacre at two New Zealand mosques, live-streamed to the world, was not the first internet broadcast of a violent crime, but it showed that stopping gory footage from spreading online persists as a major challenge for tech companies despite years of investment.
The massacre in Christchurch was live-streamed by an attacker through his Facebook profile for 17 minutes, according to a copy seen by Reuters. Facebook said it removed the stream after being alerted to it by New Zealand police.
But a few hours later, footage
