From online outrage to a real-life mob, descending on a Swedish school

Perhaps because it was so very quiet when I lived there, but every report of a riot in Gothenburg shocks me, and the latest is in any case extremely odd.

According to the local paper, the police had to keep a crowd of about 500 schoolchildren out of the Plusgymnasiet sixth form college after a rumour spread that there was a girl hiding there who had opened an Instagram account with which to mock other girls at school. The account – according to an earlier story – had picked up 6,000 followers inside a couple of days: it consisted of photographs of teenage girls from most of the poorer suburbs of the city, lifted from Facebook accounts or Twitter profiles, and decorated with cruel remarks about their appearance and insults like "scrubber" and "slag".

This was obviously a horrible thing to do. In itself it shows the way in which social media promotes antisocial behaviour. The impulses behind it must be familiar to anyone who felt unpopular or excluded as a teenager – obviously the popular and included ones can get their snark on within a circle of friends. Very little can make a miserable child feel better than the sight of another being even more miserable and powerless. But without computer networks, you can only stalk the streets muttering to yourself about how the world is full of loathsome losers or hang around at the edge of the dance floor, loathing and being a loser. With Instagram, or any similar service, you can publish this nastiness to all the world.

And the world loves it. That's one reflection. Six thousand people did not follow the account to think seriously that the person who made it needed help, but because it appealed to their own nastiness. There are large parts of the Mail's sidebar of shame that appeal to the same emotions and that's the largest website in the British newspaper industry.

So far the story tells us nothing much new. Nor is it surprising that at some stage the tide of emotion reversed and what had first pleased the audience suddenly disgusted them. The Mail, after all, made a solemn promise to give up papparazzo photographs after the death of Diana.

But in place of a "Twitter storm" or similar confection of outrage, what happened next was an attempt at physical assault. "She's going to be punished. We're here to take revenge" said one of the crowd to Expressen's reporter.

This is why there were 30 police cars and a helicopter summoned to the school. Obviously, in a crowd of 500, about 400 are going to be there to see what happens and to share the excitement. The number prepared actually physically to harm the perpetrator will have been small. But how many are needed? Even in real lynchmobs, most of the crowd were spectators.

The online world and the physical one have here blurred into one thing, and it is dominated by the same old primate passions. There's a lot missing from the newspaper accounts – it's possible, for example, that there was an aspect of race or class hostility in the choice of victims. But one thing looks clear enough. Here, in what was one of the most modern and peaceful cities of the 20th century, the dynamics of a witch hunt have emerged with brutal clarity from our paleolithic past. I know it's progress that the whole thing was tamped down quickly. But I can remember when Swedes honestly believed they had been lifted by progress far above the moral squalor of their ancestors. It turns out that it wasn't very far at all.