London, June 18, 1999. What a day, a day to lift the spirits after weeks stuck between a rock and a hard place and of terrible arguments with old comrades over the madness of Kosovo. Finally it is J18, our chance to come together, our chance not to play the passive spectator, but to join in a world day of action against global capitalism and its inhumanity.

The sun is shining and hot even as I listen to the morning radio reports: climbers have rappelled down the Tower Bridge, closing it with a low-slung banner; police, descending on ropes of their own, are trying to take it down. Of its own accord, London's underfunded underground train system is breaking down. Cyclists out in force are closing off streets around Blackfriars. Marchers have shut down the Bank of England; a ring of people surround the Treasury.

This is coordinated decentralization, and the cops don't know how to deal with it. They're used to control - all those easy years escorting leftist marches to Trafalgar Square, always at a pace that made your feet hurt. Today's protests have the police - and traffic news radio - working overtime.

The Carnival kicks off in Liverpool Street station and the drums are loud and thrilling on the stone floor. It's as though the huge concourse, designed for the discomfort of travellers, has just been waiting all these years for a rave. Here it is, and we snake out with the drums to a dead plaza with a McDonald's and a brazen office block of the Thatcher era. The pounding rages on as mountaineers climb up the office block to dance on the parapet. Beyond our wild cheering, the office security stares out the windows - today, they are the passive spectators of what is normally their undisputed territory.

Someone gives us green masks, a product of the Gift Economy of selfless and anonymous work that is making all this happen. Around us, others swirl past in masks of red or gold. I turn my mask over and find a suggestion inside: "On the signal follow your color. Let the Carnival begin." There is also a declaration: "Those in authority fear the mask, for their power partly resides in identifying, stamping, cataloguing - in knowing who you are. The wearing of a mask symbolizes the rejection of the cult of personality so crucial to consumer capitalism. While the elite gangs of state and capital become evermore faceless their fear of the faces of everyday resistance grows."

So we are with the Greens and as our moment strikes a thousand of us break away from the crowd. We have no leader, but messages pass through our number in a spirit of trust. This is a Magical Mystery Tour to be enjoyed.

We pour through the streets, our whistles and drums inviting those in the offices to join us. At Aldgate East station, the few cops let us stream through. The word is out to hop a westbound train, but the first train doesn't stop, nor the second. As a third train full of blank-faced passengers rushes by, the Green trust is suddenly shaken. Feels like a trap down in the tube, but we make it back to the street and turn again towards the heart of the city, completely taking over the street. Traffic halts. Tourists wave from sightseeing buses. Security guys stand in bank doorways. So many faces from so many windows. One angry guy wants to smash our faces in - but "there are too many of you."

Precisely.

Up around Fenchurch Street, and then suddenly we are all re-united, masks of all colors right in the belly of the urban beast - the LIFFE building, where computer keyboards send billions of dollars whizzing round the globe 24 hours a day. A cobbled street running along the building and down to the Thames River has been blocked off and a hydrant opened to free a 40-foot waterspout. The drums beat out against the alien buildings, we're dancing and singing in the rain, and under the cover of the sound and fury anonymous hands brick up some LIFFE entrances and smash others. We block up the drains, flood Dowgate Hill and take a rest among other joyous faces on a tiny bit of beach on the Thames, the Thames that is everywhere enclosed by private capital. We sit there in the sun and smoke a spliff.

The huge LIFFE building bridges Cannon Street, and by the time we return, so does a giant banner: "The Earth: A Common Treasury For All." This is Precise Protest - protest where it matters. Musicians have taken over an underground car park; the drums beat on. More banners are hoisted, some tied to the street security cameras that keep a constant vigil. Everywhere there is an attack on what some have called the New Enclosures: private capital's takeover of the river, of public space, of the city itself. We are not, then, "a mindless mob," but an international force against finance fetish and global enclosure for profit.

We take a break for a drink and return to a changed mood. News spreads quickly: a young woman has been run over by a police van; some fearless youth have stormed the LIFFE building. Now the cops show themselves. They are hot, they have been given the runaround, they have their new telescoping batons, their shields and all-in-one helmets. But they have never dealt with the fast-moving fearlessness of the generation who are the children of us middle-aged "anti-capitalists."

And then they are on the charge. Adrenaline jacks up. Bottles begin to fly into the faces of the police. Protesters dressed in suits of irony pull flare canisters from their suitcases and hurl them. A luxury Mercedes showroom is trashed and another bank attacked as the police charge is held off.

Now the words on my mask seem prophetic. It is the day after the Carnival, and the radio reports have a much different tone. Fourteen people have been arrested. The police say they will immediately begin studying hundreds of hours of street security camera footage to add to that number. Some three months ago, I picked up the newspaper and read how keen the cops were to infiltrate Reclaim the Streets and other groups organizing J18 in London. Now they have just 14 arrests to show for their efforts, and there will be debriefing sessions called, new containment plans drafted. Of this you can be sure: they will secure their enclosures. And as J18 in London showed, a generation of young people will once again prove ready to break down their every barrier.

Taken from Adbusters at www.adbusters.org