The man who killed 51 people at two mosques in New Zealand broadcasted his attack on Facebook. In October of that year, a man in Germany broadcasted his own mass shooting live on the popular livestreaming site.
On Saturday, a man in Buffalo, N.Y., killed 10 people and injured three more at a grocery store in what the authorities said was a racist attack. The authorities identified the shooter as an 18-year-old who wrote in a manifesto that he had been inspired by the others.
The video of the Buffalo shooting was taken down within two minutes of the start of the violence. Two minutes was all it took for the video to be shared.
Links to the recordings of the video were found on other social platforms. A clip from the original video was posted on a site called Streamable and viewed more than three million times before it was taken down. A link to the video was shared hundreds of times on Facebook and on the micro-blogging site.
Questions about the role and responsibility of social media sites in allowing violent and hate-filled content to flourish are raised by mass shootings and live broadcasts. Many of the attackers in the shootings have written about how they developed their racist and antisemitic beliefs after watching other attackers live on the internet.
It's a sad fact of the world that these kind of attacks are going to keep happening, and the way that it works now is on a social media aspect as well. It's just a matter of when.
There are questions about the responsibilities of social media sites. The discussion has been raised since Musk said he wants to make unfettered speech on the site a primary objective.Daily business updates The latest coverage of business, markets and the economy, sent by email each weekday.
Social media and content moderation experts said that the quick response from twitch was the best that could be expected. The fact that the response did not stop the video from being spread on other sites raises the question of whether the ability to livestream should be so easy to access.
I'm impressed that they got it down in two minutes, but if the feeling is that even that
The site's rapid action was very strong and shows good progress, according to a statement from the vice president of trust and safety.
She said that if ever, that content or behavior stays contained on one platform, we are all part of one internet.
In a document that appeared to be posted to the forum 4chan and the messaging platform Discord before the attack, Mr. Gendron explained why he had chosen to stream on Twitch, writing that it was compatible with livestreaming for free and all people with the internet could.
It is possible for anyone with an account to go live, unlike sites like YouTube, which requires users to verify their account to do so and to have at least 50 subscribers to stream from a mobile device.
I think that livestreaming this attack gives me some motivation in the way that I know that some people will be cheering for me.
He said that he had been inspired by far-right sites like The Daily Stormer and the writings of the Christchurch shooter.
Gov. Kathy Hochul of New York criticized social media platforms for their role in influencing Mr. Gendron's racist beliefs and allowing video of his attack to circulate.
Ms. Hochul demanded that social media executives evaluate their policies to make sure that this information is not spread.
There may be no easy answers. The experts said that platforms like Facebook have made strides in removing violent content. In the wake of the shooting in New Zealand, social platforms and countries around the world joined an initiative called the Christchurch Call to Action and agreed to work closely to combat terrorism and violent extremism content. Social sites use a shared database of hashes, or digital footprints of images, to flag inappropriate content and have it taken down quickly.
Ms. Douek said that Facebook seemed to have fallen short. According to CrowdTangle, a web analysis tool, some Facebook posts that linked to the video posted on Streamable generated more than nine hours of interaction.
When users tried to flag the content as violating Facebook's rules, which do not permit content that glorifies violence, they were told that the links did not run afoul of Facebook.
A Facebook spokesman said that the posts do violate the platform's rules. The spokesman did not have an answer when asked why some users were told that posts with links to the video did not violate its standards.
In many cases, the shooting video had been uploaded directly to the platform, despite the fact that many posts with links to it had not been removed. A company spokeswoman initially said the site might remove some instances of the video or add a sensitive content warning, then later said the site would remove all videos related to the attack after The Times asked for clarification.
A spokeswoman at Hopin, the video conferencing service that owns Streamable, said the platform was working to remove the video and remove the accounts of people who uploaded it.
It is going to be difficult to find violent content.