Australian Prime Minister Scott Morrison has called for a global crackdown on social media after footage of last Friday's mosque attacks in Christchurch, New Zealand was livestreamed on Facebook, calling into question the extent to which the world's biggest tech giants can successfully monitor their own platforms.
Morrison shared the letter in a Twitter post on Tuesday.
"It is unacceptable to treat the internet as an ungoverned space," the Morrison's letter read.
"It is imperative that the global community works together to ensure that technology firms meet their moral obligation to protect the communities which they serve and from which they profit."
Facebook and Alphabet's YouTube are among those to have faced heavy criticism for their failure to block videos of last week's twin shootings, which left 50 dead and several others critically injured.
Facebook confirmed on Monday that a livestreamed video apparently showing last week's attack was viewed 4,000 times before it was removed.
During the livestream itself, the video was viewed fewer than 200 times, but views racked up after news of the attack broke. The footage was later shared on other platforms, including YouTube and Twitter.
Facebook said on Saturday that 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." Reddit, Twitter and YouTube also tried to move quickly to remove content related to the shooting.
—CNBC's Arjun Kharpal contributed to this report.