WITH stunning speed, protests that started on June 6th in São Paulo over a 20-centavo (nine-cent) rise in bus fares have escalated into the biggest nationwide street demonstrations Brazil has seen since 1992. Then, citizens took to the streets to demand the impeachment of a president on corruption charges. What they want this time is less clear. The first protests were dismissed by paulistanos unsympathetic to the organisers’ demand for universal free bus travel (a policy that would cost the city 6 billion reais a year, the mayor, Fernando Haddad, pointed out). Commuters were unimpressed when the protests made their hellish journeys even worse, and outraged by the vandalism committed by a hard core. Conservative newspapers called for a crackdown.

All that changed on June 13th when ill-trained, brutal police turned a mostly peaceful march into a terrifying rout. Officers with their name tags removed fired stun grenades and rubber bullets at fleeing protesters and bystanders, and hunted stragglers through the streets. Motorists trapped in the mayhem were hit with tear gas. Demonstrators caught carrying vinegar (which lessens the effect of the gas) were arrested. Several journalists were injured, two shot in the face at close range with rubber bullets. One is likely to lose sight in an eye. The following day’s editorials took a markedly different tone.

By June 17th what has been dubbed the “V for Vinegar” movement or “Salad Revolution” had spread to a dozen state capitals as well as the federal capital, Brasília. An estimated 250,000 took to the streets across the country the following nights. There were many more women, families and middle-aged folk than at the initial protests. The demands had also grown more varied: banners condemned corruption, rising prices, poor schools and hospitals, and the cost of next year’s football World Cup, for which Brazil will spend 7 billion reais on stadiums alone—three times the cost of South Africa’s 2010 World Cup. “First-world stadiums, third-world schools and hospitals”, ran one placard.

São Paulo’s state security chief, Fernando Grella Vieira, ordered police not to use rubber bullets and to stand by unless the protest turned violent. That reduced the mayhem, though on June 18th a splinter group tried to break into City Hall. In Rio de Janeiro the state-government building was damaged and banks and shops looted. In Brasília demonstrators scaled the roof of Congress. On June 19th protesters clashed with police before a football match between Brazil and Mexico in Fortaleza. But most of the marches passed off without serious violence.

Small protests have recently escalated into mass movements in other countries, including Britain, France, Sweden and Turkey. Those countries variously suffered from high youth unemployment, ethnic conflict, falling living standards, authoritarian government and worries about immigration. Brazil is a different story. Youth unemployment is at a record low. Brazilian racism is an internalised reality, not a daily street battle. The past decade has seen the biggest leap in living standards in the country’s history. As for immigrants, though Brazil was built by them it now has hardly any. Only 0.3% of the Brazilian population was born abroad.

That has left commentators—and some marchers—struggling to explain why Brazil has taken to the streets. There is no shortage of causes. Violent crime and political corruption are endemic; police brutality is commonplace in poor neighbourhoods. Crack cocaine is sold and consumed openly in every big city. Brazilians pay taxes at rich-world rates (36% of GDP) and get terrible public services in return. The cost of living is startling. A minimum-wage worker in São Paulo whose employer does not cover transport costs (an obligation for formal employees) must spend a fifth of his pay to slog to work on a hot, overcrowded bus from the city’s distant periphery.

But none of this is new. In fact, the past decade’s economic growth has brought the biggest gains to those at the bottom of the heap. So why now? One reason is that the world is watching: the Confederations Cup, a dress rehearsal for next year’s tournament, kicked off on June 15th. Another is a recent spike in inflation, which is eating into consumers’ buying power just as a credit binge has left them overstretched.

São Paulo’s bus fares have not risen since January 2011 (fares are routinely frozen in municipal-election years, such as 2012, and this year Mr Haddad agreed to wait until June before a rise in order to help the federal government massage the inflation figures). Twenty centavos does not even make up for inflation since the most recent fare increase. But unlike housing and food, which are also getting costlier, bus fares are under government control. That makes them a lightning rod for anger about broader inflation.

By June 19th majors all over Brazil were rushing to cancel the fare rises, including in São Paulo. It is, sadly, too late to bring sanity to spending on stadiums for the World Cup. And the diffuseness of the protesters’ broader demands makes it hard to see how they can be met, at least in the short term.

Dilma Rousseff, the president, has tried to position herself on the side of the protesters. The demonstrations proved the power of Brazilian democracy, she said on June 18th, adding that the new middle classes “want more, and have the right to more”. Her popularity, high for a mid-term president, may come under pressure. But although it is her own policies that have stoked inflation, her re-election next year does not seem to be immediately threatened. Few protesters sported signs of party affiliation and the opposition is weak.

Nonetheless, her government has been put on notice. In the past decade 40m Brazilians have escaped absolute poverty. Most are still only one payday from disaster, and will fight tooth and nail not to fall back. They see further gains in living standards as a right. The marches are a sign that they are waking up to the fact that they pay taxes and deserve decent public services, not just shiny stadiums.