Brazil is bracing for the first wave of nationwide demonstrations against staging the World Cup after activists called for action on social media.
With less than five months to go before the June 12 kick-off – when the five-time champions and hosts take on Croatia – Brazil is again facing the social rumblings which marred last year's Confederations Cup dress rehearsal.
Radical protest group Anonymous called for protests via its Facebook page under the slogan, "The Cup will not take place" while "FIFA go home" was another term which appeared on Twitter, referring to football's world governing body, which will be watching the weekend's events nervously.
Brazilians are avid users of social media, which is a favoured tool to organise protests.
Many in football-mad Brazil say they are not against the World Cup as such – their country is the most successful nation in the tournament's 84-year history.
They are angry to see hundreds of millions of dollars spent on preparing 12 host cities for the sports jamboree when poor infrastructure and areas such as health and education require urgent massive investment.
Anonymous, which has staged a number of highly publicised stunts in different countries, says Saturday's protests in 36 cities across Brazil – a nation of 200-million – "will be followed by others."
In Rio de Janeiro, scene of repeated demonstrations – some of them violent – since last June, protesters are set to meet at 5pm in front of the luxurious Copacabana Palace Hotel, just off the city's famous beach.
In Sao Paulo, the rendez-vous is the city's Masp art museum on the central Avenida Paulista thoroughfare.
Other cities expecting demonstrations include Salvador, Porto Alegre, Belo Horizonte, Curitiba and the capital Brasilia.
"In Rio, 4 000 people have confirmed their presence on social media," a lawyer aiding residents evicted from their homes as organisers spruce up the area around the city's Maracana stadium told Agence France-Presse.
"We are expecting between 500 and 1 000 will show up. Bring your gas mask!" she added.
A spokesperson for Sao Paulo's "free pass" student movement, which sparked last summer's protests at transport fare rises, told AFP that they "support the demonstrations but will not participate."
Spokesperson Caio Martins explained: "We can't be everywhere."
Rio's state secretariat for public security told AFP that "intelligence services have been constantly monitoring" social media sites since last year's demonstrations, which initially stunned the authorities.
"Public demonstrations are part of democracy, but if there is vandalism, security forces will intervene," the secretariat told AFP by email.
After starting off last June the demonstrations progressively became more radical – and violent – before fizzling out.
Brazil has been hit in recent weeks by fresh unrest of a different kind with "rolezinhos," or flash mobs primarily comprising youths from slum areas, swooping on shopping malls in swanky districts of Rio and Sao Paulo.
Bans have been slapped on them to stamp out the craze.
University of Rio (Uerj) sociologist Jose Augusto Rodrigues says it is difficult to tell if calls to protest will be followed on Saturday.
"Things are bubbling under to a certain degree on the social media sites after the ban on 'rolezinhos.' But it's hard to say if people will show or not. It will be a means of taking the temperature" of disaffected youth as the World Cup looms into view, Rodrigues said.
"What will happen will also depend on how the police react. If there is repression, that will underpin solidarity" among the protesters.
He added, "There will be protests during the World Cup, particularly as it is a general election year, but not on the scale of last June.
"People have lost the desire to demonstrate owing to the radicalisation of certain protest groups, while the authorities for their part have learnt to keep the protests under control."
Another Uerj sociologist, Alba Zaluar, said: "Those who call for rejection of the World Cup have forgotten to consult the Brazilian people," given that polls indicate a solid majority back the event.