The violent unrest that has broken out in multiple towns across England and Northern Ireland this week feels simultaneously shocking and familiar.

Rioters have rampaged across more than 15 towns and cities, looting businesses, injuring police officers, attacking mosques and targeting hotels that house asylum seekers. Britain has had sporadic outbreaks of semi-organized mob violence for decades, including brawls by infamous “firms” of soccer hooligans in the 1980s and ’90s, an outbreak of race rioting in northern England in 2001 and a spate of rioting and looting centered on London in 2011.

But some circumstances are markedly different. While the 2011 unrest was sparked by the police killing of a Black man, these riots have stemmed from far-right disinformation on social media. Online influencers opposed to immigration spread the false claim that an asylum seeker had killed three children last week in Southport, England, and called their supporters to attend “protests” against the supposed threat. Many of the gatherings erupted into violence.

More far-right protests had been expected on Wednesday, but with a heavy police presence on the streets, they did not materialize on any large scale. Instead, thousands of antiracism protesters gathered in cities across the country.

Most Britons and most elected officials have recoiled at the anti-immigrant violence, indicating that for now, it has hurt the nativist cause more than helped it. But in the long run, experts say, the effects are much harder to predict.

A number of politicians and pundits from the anti-immigration right, while condemning the violence itself, have claimed that the unrest is evidence that immigration needs to be restricted, even though it arose out of false online claims about a migrant attack. (In reality, the suspect is British-born and his parents, according to the BBC, are from Rwanda.)