"Hey, I want my money back!"

The young man in the grey sweater came to Oxford Street to buy a mobile phone; he isn't part of the gang of activists who have just occupied Vodafone's flagship store. The protesters are in their early twenties, and equipped with banners and placards demanding that the mobile phone company pay the £6bn in tax that the government allegedly waived earlier in the year, despite the Chancellor's insistence that £7bn-worth of cuts to welfare benefits are "necessary".

This young man isn't part of the group, but he flings himself behind the official cordon, yelling and waving to his friends, who all laugh and get out their mobile phones to take pictures of him. It's a little bit like a Vodafone advert, apart from all the police.

The first thing to note about this protest is that it has been organised only slightly more efficiently than a French farce: the young people currently squatting determinedly in the doorway of the Vodafone store were mobilised via Facebook and Twitter with real names and the intended target freely discussed, and by the time more experienced activists had intervened to give basic security advice, it was too late.

It is, as such, hardly surprising to see Her Majesty's finest waiting for us on Oxford Street, but in the mad dash to dodge the police and barricade the shopfront before the first customers arrive, the protesters giggle like children shocked by their own daring. This is not just the usual troublemakers making the usual nuisance of themselves. They are very young, they are very resolute and they are certain that the left's usual response just won't cut it anymore.

"The next five years can't just be about marching on Whitehall to hear Tony Benn speak," says Thom, 22. "We need to get creative."

The second interesting aspect to this stunt is that it is not an occupation of a government building, or council offices, or a press lobby. Vodafone have had no direct influence over the spending review that will shortly force millions of people out of work and out of their homes and communities. Vodafone do not write Treasury policy. Vodafone sell phones. The people who have gathered to protest here, however, seem to want to articulate a more profound dissatisfaction with the way the new government has decided to prioritise business at the expense of education welfare and healthcare. The public rhetoric of the state emphasises 'fairness' above all else, but those in power seem to believe that fairness is only acceptable if it does not interfere with competition.

"The cuts are not fair, we're not all in this together and there are alternatives," said another activist, Jennifer Kyte. "Why not start by collecting -- instead of writing off and ignoring -- the tens of billions owed in taxes by wealthy corporations? Isn't this supposed to be the wonderful Big Society?"

Nobody attacking the Vodafone store really expects the company to suddenly hand back £6bn to the state. The matter is settled, after all: Vodafone paid £1.25bn "to settle all outstanding CFC issues from 2001 to date and has also reached agreement that no further UK CFC tax liabilities will arise in the near future under current legislation." Still less does anyone expect that the coalition, which seems to have determined in the coldest reflex of disaster capitalism to use the occasion of the recession to destroy welfare once and for all, will agree to use the money to make sure the poor don't starve this winter. They just want the government and big business to know that unlike Alan Johnson, they can count. They can count, and they don't like the numbers.

All of this feels just a little bit more thrilling than the average rainy protest. Even harried commuters stop to see what's going on. "I -- am -- speechless!" enunciates a woman in a smart pink coat. "What, I pay my taxes but they don't have to because they're a big company?" She fiddles with the police cordon. "I'm not saying everyone on benefits should be, OK, but I have a friend with five kids, her youngest is eight months, and they've just taken away her benefits, and now you're telling me they let Vodafone off six billion? How's she going to look after her baby now?"

Suddenly, there are screams from the shop entrance. The security doors are coming down and police have shoved themselves into the shop and started dragging out as many people as they can, by their feet if necessary, "for their own safety". A girl in a green jumper is pushed roughly to the floor and the rainswept pavement writhes with forcibly twisted limbs as one young man struggles out of the melee and hollers "Police brutality on the streets of London!" for the benefit of the horrified crowd. We can see what's going on perfectly well.

We can see the police jostling students to the ground. We can see knees going into backs, arms around necks. The small area in front of the Vodafone store has been cordoned off with two violent bandages of red-and-white police tape, and now the agents of the state have surged in to cauterise the wound. Some protesters are now trapped inside; some are linking arms outside the rows of police that now seal off the storefront like a matt black scab. The energy spills out onto the pavement. Like the company they have targeted, these young people are clearly determined to Make The Most of Now.

With the activists waving a small sea of identical placards with the Vodafone logo and the legend 'tax dodgers', a circle of onlookers get out their phones and start taking pictures. You half expect to hear a smooth voice actor announcing price plans over the cheesy strains of the latest indie-pop sensation, but real life is wetter and angrier than the adverts. All you can hear is the wail of distant sirens.