Thousands took to the streets across Brazil recently in the country's second "March for Freedom", which saw a colourful collective of organisations protest together for the right to free speech, freedom of choice and, some, for the legalisation of marijuana. The mood was a mix of protest and celebration, in an event that marks a pivotal moment in the struggle for liberal values in Brazil.

More than just a march, the March for Freedom (Marcha da Liberdade) represents a new social movement that emerged just one month ago, in response to the increasing violent repression of protesters by state military police. Police violence is a reality that many face in Brazil, especially in areas where crime and poverty are high. Yet the escalating force used to quell peaceful protests has surprised many. The catalytic event came on 21 May this year at Sao Paulo's "marijuana march". Despite a crowd of little over 1,000, police launched an offensive armed with rubber bullets, tear gas and pepper spray.

The police were acting under a federal court ruling, which had declared pro-marijuana marches illegal. At least nine other federal courts across the country also issued a ban. The courts claimed that the protests acted to support drugs use, a crime in Brazil known as "apology for drug use". However, the rulings only served to increase support for the marches, with many protesters joining in under the banner of freedom of expression.

Then, in a coup for free speech and liberal values, earlier this week Brazil's supreme court voted unanimously to overturn the rulings and to allow Brazil's marijuana marches to go ahead. The ruling came just in time for last weekend's marches. Despite a heavy police presence, all protests, except one, took place in peace.

The protests and the ruling have also thrown fuel onto Brazil's ongoing debate on drugs laws and the war on drugs. Like its Latin American neighbours, Brazil knows only too well the problems of drugs-related crime and the militarisation of the police. Public and political debates have become increasingly critical of the war on drugs.

Indeed, the movement to review drugs laws in Brazil is gaining ground. This has been strengthened by the surprising intervention of former President Fernando Henrique Cardoso, who has made a complete u-turn on the issue since leaving office. Cardoso is now chair to the Global Commission on Drug Policy. The commission released a report earlier this month calling for the decriminalisation of marijuana, and a debate on the decriminalisation of other substances. The report notes:

"The starting point for this review is the recognition of the global drug problem as a set of interlinked health and social challenges to be managed, rather than a war to be won."

Portuguese drugs policy is held up as a successful example, among others. The report is drafted by a panoply of former world leaders including Cardoso, former Colombian President Cesar Gaviria, former President Ernesto Zedillo of Mexico and former UN Secretary General Kofi Annan, among others.

Cardoso has also taken his battle to the screens, with the launch of a documentary earlier this month called Breaking the Taboo. The documentary highlights the perils of debating an issue so clouded by ideology, and calls for an end to the stigmatisation of the debate. It boasts the support of several former world leaders including Bill Clinton and Jimmy Carter. Unsurprisingly, the campaign has proven less successful in finding politicians currently in office to support its cause. It's clear that the stigmatisation surrounding drugs issues continues to stifle the debate; it's certainly not a vote-winner.

But perhaps things are changing. Coverage of the marijuana march and Cardoso's documentary recently won an extended prime-time slot on one of Brazil's most popular TV shows, Fantástico. Following Saturday's march, the influential newspaper Folha de Sao Paulo dedicated Sunday's editorial to the subject, calling for an open debate on both decriminalisation and legalisation.

It's clear that those in favour of changing drugs policy continue to be a minority, but the violent repression of May's march and this week's supreme court ruling have thrust the issue into the spotlight in a new way. Although the protesters are far away from winning the war on drugs policy, they have succeeded, for now, in winning the public's gaze and the court's protection. More significantly, the court's ruling marks a symbolic step for Brazil, which may help "break the taboo" and open up the debate on how best to manage drugs in a post "war on drugs" world.