Addressing the nation from his Downing Street office and residence, Starmer pointed the finger at the role of the firms in two nights of violence after Monday’s stabbing spree in the seaside town near Liverpool.
“Let me also say to large social media companies and those who run them: violent disorder, clearly whipped up online, that is also a crime,” the UK leader said.
“It’s happening on your premises, and the law must be upheld everywhere.”
Monday’s attack left three young girls dead and five more children critically injured alongside two adults.
A 17-year-old, named Thursday as Axel Rudakubana, has been hit with a slew of murder and attempted murder charges.Social media platforms like X have been heavily criticised for helping to spread misinformation about the suspect, including around his identity, faith and background.Speculation online that he was Muslim or an immigrant helped fuel anger around the attack, according to experts, with rioters targeting a mosque in the Southport disturbances.
In his remarks, Starmer acknowledged there was “a balance to be struck” by social media platforms over tackling misinformation online while permitting free speech.
But he warned: “Inciting violence online is a criminal offence and that is not a matter of free speech. It is a criminal offence.”
The country’s former chief prosecutor, the UK leader added platform providers’ services were “an amazing opportunity that we all enjoy as a country” but cautioned “there is also a responsibility that goes with it”.
“That’s a space for a mature conversation to take place,” he said.
Starmer was speaking after meeting UK police chiefs to discuss the two nights of unrest seen since Monday’s tragedy.
He vowed “we will take all necessary action to keep our streets safe” following the Downing Street discussion.