"Over the past several years the Mission has been colonised by pigs with money," the posters ranted. "This yuppie takeover can be stopped and turned back ... Vandalise yuppie cars! Break the glass, scratch the paint, slash their tires and upholstery. Trash them all!"
Thus the Mission Yuppie Eradication Project announced itself, a group fond of early 20th-century Russian revolutionary theory and with a mordant wit. In English and Spanish, its posters urged the Mission's traditional working-class and immigrant poor to rise up against cocktail bars, sushi restaurants and men in suits and ties. Action soon followed, in the form of random vandalism and graffiti telling the "cigar-bar clowns" and "yuppie mayonnaise" to go back to Yuppieland.
For the past few months, San Franciscans have been unsure how to take the Project: as a joke, a threat, or a genuine movement. This is a city appalled by its own encroaching gentrification, which would like nothing more than to return to its past as a launchpad for carefree revolutionary theatre. On the other hand, who wants their cars and favourite restaurants trashed because of some nutty group with a catchy name?
Recent events have conspired to complicate things even further. An ad appeared in the San Francisco Weekly, an alternative magazine that has found itself endlessly amused by the Project's antics, announcing a counter-demonstration in which yuppies would stand up for their rights to wealth and property and denounce this campaign of hateful discrimination against them. So the city braced itself for a showdown last Sunday in the Mission's Dolores Park.
Nothing, however, turned out as expected. The ad turned out to be a hoax concocted by the Weekly for its own subversive purposes, and although more than 200 people showed up, the slogans at the demo - "Make Lofts Not War!" and "Give Greed A Chance!" - were no more than pranks to make fools of the media and the few genuine yuppies in attendance.
Now, everything is in a high state of confusion. A group calling itself the European-American Issues Forum is circulating a petition accusing the Yuppie Eradication Project of racial discrimination against rich whites. Rumours are flying that the head of this Forum - assuming it really exists - is a member of the Aryan Nation. As for the Weekly, it is being roundly condemned for breaching journalistic ethics and glamourising vandalism for the sake of upping its readership.
Is this political theatre, or pure farce?
The key surely lies with the mastermind of the Eradication Project, a 38-year-old film-school drop-out who calls himself Nestor Makhno, after an obscure Ukrainian revolutionary. The police call him an anarchist; he says he is "a left Communist influenced by the Situationists - but why split hairs?"
Unfortunately for Mr Makhno - or, to use his real name, Kevin Keating - the police spotted him roaming the Mission in the dead of night a couple of months ago with a large pot of wall-poster glue. They decided to trail him and, they say, saw him vandalising cars and generally acting in a suspicious manner.
And so, at the end of last month, they burst into his apartment, hauled him off in handcuffs and turned the whole place over in search of evidence of terrorist intent.
Their ragtag haul included books with menacing-sounding titles such as Killing Can Be Fun (just a harmless piece of pulp fiction); two copies of Man's Fate by Andre Malraux ("and it's not even that compelling a book!"); lots of revolutionary tomes; a bag of organic black beans that the police thought might be fertiliser for making bombs; a mountaineering axe (but not, curiously, the three copies of Crime and Punishment that might have given their owner ideas on what to do with it); a computer containing his novel-in-progress and the text of the infamous posters; and the print of an almost completed 16mm film.
The police will probably be intrigued by the novel, which is about a young restaurant worker who sets fire to expensive cars in the Mission district and kills two policemen. The film is also quite a trip, telling the story of a homeless Vietnam veteran who tramps round the financial district in search of a man he saw raping and killing an innocent woman before concluding that he'll never find him because all the yuppies in business suits look like rapists and murderers to him.
More seriously, the police also claim that they found an acid-bomb recipe and, bizarrely, some confidential personal-account statements of Mission district residents stolen from a prominent brokerage firm. For the moment Makhno-Keating is back on the street, but the authorities have hinted that they may be pressing new charges against him once they have sifted through the evidence.
There is no doubt he is serious about his hatred of capitalism and the intrusion of yuppie condominiums and warehouse conversions that push rents up for everyone else. But he is also a bundle of contradictions: he claims to be non-violent, but advocates the "destruction" of expensive restaurants; he claims to be an enemy of the bourgeoisie, but his girlfriend used to work for a brokerage firm (the same one that the stolen account statements came from); and he shows no shame in stuffing his face in fancy French restaurants when someone else is paying.
"I know, I even look like a yuppie," he gaily admits.
So is this a revolution, or a one-man joke? "We are more than one but less than a hundred," he responds enigmatically. And that's as much as San Francisco is going to find out, for now.