Determined to rein in protests which have marred the build up and threaten to overshadow the event, Brazilian authorities have vowed to crack down hard on violence in a bid to ensure the World Cup goes off without a hitch.
Brazil was caught out by the biggest protests in a generation last June during the Confederations Cup dress rehearsal event, which saw more than one million people take to the streets. (Suggested read: With 100 days left, last-minute Brazil vows to be ready)
Some protest groups have vowed to keep on marching to protest the billions being spent on the Cup in a country whose public services need a massive overhaul.
Recent protests have been small, many Brazilians staying away appalled at how radical anarchists known as Black Bloc have injected a violent edge into proceedings. (Also see in pics: Why football-loving Brazilians do not want World Cup)
President Dilma Rousseff and her administration say violence is totally unacceptable and have vowed to clamp down, if necessary, by sending in the army and police trained in martial arts.
Last week, Brazil said it would deploy 150,000 police and soldiers and also bring in 20,000 private security officers across the 12 World Cup host venues to head off protesters whose slogan is "the Cup will not take place."
The government is taking seriously the continued presence of the radical fringe, despite recent marches only attracting 1,000 or so people in Rio de Janeiro and Sao Paulo, which have ended in brutal confrontations between protesters and military police accused in some quarters of over-reacting.
The authorities have ramped up their efforts to tighten security since the death following a February 6 protest in Rio of a TV cameraman, struck in the head by a flare thrown by a youth.
"We will not accept this kind of thing; we must nip it in the bud," insists Rousseff.
The government is looking to pass parliamentary legislation strengthening the penal code to deal with protesters who resort to violence and vandalism while also framing new anti-terrorist laws long in the offing but which have little chance of reaching the statute book before the June World Cup.
Some lawmakers want to see protester violence branded "acts of terrorism".
The issue is a delicate one for the leftist ruling Workers Party which protested against the 1964-1985 military dictatorship as well as corruption while in opposition and looks on public protest as a basic freedom.
"Terrorism is one thing; other crimes should be described differently," indicates Justice Minister Jose Eduardo Cardozo, among those who favor banning the wearing of masks at marches.
"On the one hand we must guarantee the freedom and protect those who wish to give vent to their feelings democratically. On the other hand, we cannot allow people to use the demonstrations to kill, injure or vandalize," Cardozo says.
As the debate rages, so the military police have been trying to refine their methods of reacting to the protests.
- 'Ninja officers' -
They debuted a new technique in Sao Paulo during an anti-Cup march on February 22, deploying at ultra-close quarters dozens of officers well versed in martial arts, so-called 'ninja' police.
They made 220 arrests, including five journalists, citing intelligence "information" that trouble was brewing.
As the police mull how to limit trouble, so some of the 12 World Cup venues are looking at home to limit opportunities for it.
Another potentially worrisome issue is Fan Fest areas for ticketless fans to congregate and watch matches on giant screens.
Recife, in the north, says it is scrapping the idea, not least as the local authorities will have to foot the bill -- one of the causes celebres of the protesters who want to see less spent on the tournament as it is.
But there is the additional concern that the areas would be another potential theater for troublemakers away from the stadium, where police resources would already be concentrated.
Recent incidences of hooliganism in Brazil have meanwhile been greeted with alarm abroad, even though Cup organizers and FIFA say they have faith in an integrated security system to keep fans of the 32 national teams safe.
Last year saw 30 football-related deaths in Brazil, though hooliganism tends not to hit the national side.
Violence persists with drug trafficking still rife despite recent slum "pacifications" and robbery is a regular occurrence in several Rio tourist havens.
Rousseff is optimistic Brazil will rise to the security challenge.
"Brazil is prepared to ensure the security of its citizens and visitors. If need be we shall send in the army," she insists.