Yesterday the media and Twitterati went wild for a video clip showing a female cyclist in London ripping the wing mirror off a van after its driver said sexist things to her. Filmed by the helmet cam of a man on a motorbike, the clip showed the foul-mouthed, common-sounding van man calling the woman an ‘old dog’ and asking her ‘You on your period?’ after they had some kind of road-space altercation. The woman furiously cycles after the van and when it comes to a standstill in a side street she yanks off its mirror. The motorbike guy then bellows at the men in the van: ‘You deserved that. YOU SCUM.’

The video instantly went viral. It was viewed 10million times on Facebook. It was covered on newspaper websites. It was shared thousands of times on Twitter and other social media with air-punching internet speak: ‘You. Go. Girl.’ JK Rowling tweeted it, helping it go stratospheric. But things soon turned sour. It’s now widely suspected, and reported, that it was a set-up – not an accidentally captured London street scene but a staged piece of film work by a company that specialises in making viral videos. It’s been taken down by Facebook, and the Guardian and others are wondering why unverified videos are so often taken as gospel.

It’s a good question. And in this case there seems to be a pretty clear answer: it’s because the blokes in the video conform so brilliantly to bourgeois feminists’ view of working-class men as a nasty, sexist pox on daily urban life. If the video was a set-up, as many now suspect, then it’s a brilliant one because it taps directly into one of the uglier prejudices of our age: that the streets aren’t safe because they’re swarming with uncouth, unreconstructed men who speak with threatening urban accents and think nothing of wolf-whistling or cat-calling or abusing passing women. And for all the occasional newspapers articles that say ‘Sexism is a problem among middle-class men, too’ – back-covering much? – we all know what kind of men they’re talking about. They work on building sites. They drive vans. They read the Sun. You do the math.