Laurie Penny: It's easy to mock, but this is how real change begins

'I feel bad for you young people’ one of them tells me. 'You have all the same bullshit to deal with as us. And you don't even get Woodstock'

This isn't just about America," reads one hand-painted sign among the carpet of placards at the Occupy Wall Street protest. "It's about the whole world." The sit-ins and occupations currently springing up across the United States in response to an initial call-out by Adbusters magazine claim to be part of a "global revolution". And the first part at least is hard to argue with. Wandering through the protest camp that has now been set up for over a fortnight in Liberty Plaza in the shadow of Manhattan's financial district, at the symbolic nerve-centre of world capitalism, I am struck by how similar it is in spirit and in format to the occupied spaces I joined as part of the anti-cuts movement in London earlier this year.

The differences are cultural rather than substantive. There are the same serious young activists necking coffee over tangles of laptops and cables as they put out their messaging on social media, the same makeshift nests of sleeping bags and blankets, the same atmosphere of frenzied excitement as people from across the country arrive to swell the numbers and join the debate. Activists I meet here from the Spanish arm of what members are calling simply "the movement" tell me that this is the same explosion of popular energy that they saw in Madrid, too. It has different faces and different in-jokes but the same horizontal structure, empowered by technology, clustered with individuals sharing their own stories of hardship and struggle, and driven by the growing global demographic that commentators have identified as "unemployed graduates with no future".

In America, this is the generation that organised and voted for the Democrats in 2008. It is a generation that used to believe that "change" could be delivered through the party system, but which has had its faith shattered by circumstance. In a pile of cast-off jumpers, donated by supporters to keep the protesters warm in the chill October nights – no tents are allowed – I find a faded sweater reading "Obama '08". Now the Obama generation is beginning to understand that substantive change does not tend to happen if you ask nicely and play by the rules.

Of course, it is fairly unlikely that a few thousand soggy activists are going to be able to topple Manhattan's financial district on their own – as I write, they've got enough on their hands trying to keep the rain off their laptops. The scores of press outlets who have been asking just what this occupation stands for, however, have rather missed the point: the occupation stands for itself.

"For the first time in my life, I feel at home," reads one placard, hoisted into a tree in this impromptu peace village underneath the sparkling glass towers of Wall Street. The temporary society that has been built here is a mini-utopia of inclusivity and delicious vegan snacks, welcoming in the disenfranchised and disaffected. There's a free kitchen, library and crèche, young people wrapped in sleeping bags listening to outdoor lectures on radical economics, and a diverse cast of characters, from glassy-eyed students and excited inner-city teenagers to middle-aged union members doling out the expertise. "I feel bad for you young people," one of them tells me, "you have the same bullshit to deal with as us, and you didn't even get Woodstock." Like in London and Madrid, not everyone agrees on how to change the world, but everyone agrees that the current economic consensus is untenable – and for now, at least,that's enough.

What the protests have in common more than anything else is disillusionment with traditional politics, which are seen to be set up to protect the interests of the wealthy few. From the streets of New York to the squares of Greece and Portugal to the rain-sodden protesters currently camped outside the Conservative Party conference in Manchester, public anger is mobilising around the impression that no mainstream party, whether on the centre-left or the notional right, has the wherewithal to represent the real concerns of citizens living on or just above the breadline: the "99 per cent," as the Wall Street occupiers put it, as opposed to the "1 per cent" who own the wealth and set the agenda. Party politics is felt, rightly or wrongly, to be bloated with corporate money, poisoned by the interests of profit, and utterly unable to deal with the effects of economic meltdown on the electorate.

These protests, opening up like windows all over the world, are not a revolution, nor are they supposed to be. They are, instead, the space where revolutions can begin. They are nodes in a network of possibility where, with enough purpose and popular anger and the wind blowing in the right direction, any possible future could be imagined. They are, in short, monstrously easy to make fun of. The press, inevitably, has begun in every case by doing exactly that, dismissing the protesters as a delusional, childish, workshy bunch of "goddamn hippies", as one American tabloid put it this week.

There are certainly times when it's hard to bite back my scepticism. On a pile of blankets behind the drum circle, I meet a young man in a tie-dye shirt who tells me he's here to "ground the good energy" of Wall Street, as gusts of sandalwood incense blow over from the dodgy-looking amateur acupuncture sessions. If you think that's kooky, though, the offices towering above us are full of people who still believe the solution to aggressive free-market finance is more aggressive free-market finance. This is more than just a great big global 1968 historical re-enactment party.

It's part of what one Spanish protester, who was part of the Campa Del Sol occupation in Madrid, described as "the very redefinition of politics". There are times when the economic consensus is so overwhelming that questioning it in any way becomes a radical act, and just as they did in Europe, the US authorities are beginning to get nervous. The New York police moved on Saturday with one of the largest mass arrests in US history on Brooklyn Bridge, a stunt that seemed designed to deter activists from further dissent. But the occupiers of Wall Street have so far refused to be intimidated. For now, in a country that is beginning to reconsider what freedom actually means for ordinary people, that collective courage is enough. For now, it's more than enough.