As night fell, they took the Congress. Thousands upon thousands, they filled the capital's streets, clambered onto the roof and swamped the lawn. They had seized the seat of power, and they had the attention of the entire nation.

Brazil was convulsed on Monday night by the biggest set of protests yet, with tens of thousands of protestors marching Sao Paulo, violent clashes in Rio de Janeiro, and demonstrations in at least eight other cities. And here, in the capital, they scaled the very seat of political power, and made it their own.

The protests are vague in their nature, but crystal clear in their size and force. Some 70,000 turned out in Sao Paulo alone. There were at least ten thousand here in the capital.

Average Brazilians are deeply upset about what they see as a government that has disenfranchised them. The outcry began over the relatively small matter of a bus fare hike in Sao Paulo, but has now spread to encompass anger at the amount of money being spent - or wasted - on the Confederations and World Cups . These soccer games - with their costly tickets and expensive, unfinished stadiums - have become a match to kindling.

I walked against the flood of people to the Congress, and walked along the roof with the protestors. I looked down, seeing the police to my right in a red line. The mall had been taken, and the crowd was singing. There were vendors selling corn and candy out of the backs of cars along the rim. Behind me, people were taking pictures of demonstrators in the arc lights that illuminate Oscar Niemeyer's grand bowl. They held up signs, then posted the pictures to Facebook.

Protesters occupied the National Congress Building in Brasilia (Photo: Jamie Trecker/FOX Soccer).

The protestors were a mix; from your professional anarchists; to students; to young couples; to housewives; to rubberneckers like me. There was a heavy police presence, but there was no repeat of the ugly scenes at the Estádio Nacional Mane Garrincha on the day the Confederations Cup opened. There, police fired rubber bullets and sprayed tear gas on a group of protestors. They would later be widely condemned for using excessive force.

Those police actions galvanized the protests. They since have grown every day - along with a palpable anxiety among the upper classes in this nation. The security forces drilled on Sunday in the parking lots of the Mane Garrincha, marching in the noon heat in full riot gear. The posh hotels that line Brasilia's heart all had televisions tuned to live coverage of the destruction in Rio, and the scenes taking place only a mile to the south. It is the topic of conversation and concern from the bus stations to the pricey bars in the Pontao, on the banks of Brasilia's artificial lake.

We are assured of more unrest, and the Confederations Cup will continue to be at the center of it. On Monday in Belo Horizonte, a group tried to make their way to the Tahiti-Nigeria game. There were more protestors outside than fans inside at kickoff. It is expected that come Wednesday, the protests will roil Recife and Fortaleza, before moving on to the next match.

Where this is going is another question altogether. The protestors here in Brasilia have been peaceful, using non-violent tactics and showing no signs of danger. The protests in Rio, however, have turned ugly, with cars set on fire, windows smashed, and running battles with the police.

The march in Sao Paulo was thought to be on a knife's edge, until a deal was brokered between the police and the protest leaders.

Here, in Brasilia, they hung banners from the roof, and picnicked on the front stoop of their building. That this building, the Congress, is one of the highest-security structures in the entire nation was not lost on anyone.

That security fell on Monday. We are all waiting for what comes next.