Brazilians marching against corruption and the cost of the 2014 World Cup are also angry at the media, including the influential Globo network, accused of belittling their movement.
In Sao Paulo, the country's business and media capital, Globo TV crews have been jeered while covering protest rallies and on Tuesday demonstrators set the satellite van of another station ablaze.
Hundreds of thousands have marched in cities throughout the country over the past two weeks in Brazil's biggest street protests in 20 years.
The mainly young demonstrators have been angered public transport fare hikes and the billion of dollars spent on preparations for next year's football World Cup rather than on social programs.
The rare display of "people's power", which has forced authorities to roll back the fare increases, has received blanket media coverage, particularly by Rio-based Globo, the world's second-largest commercial TV network.
"Globo always manipulates facts and tries to put the demonstrators in a bad light, focusing on the vandalism of a few hooligans," said Leitane Luranque, one of thousands demonstrators at Monday's rally in Sao Paulo.
"And they consistently underestimate the number of demonstrators."
It is a complaint frequently heard among protesters.
Globo, part of a group that includes radio networks, newspapers and pay-TV operations, is routinely vilified on Brazilian social networks as well as in "Get out, Globo" graffiti scrawled by the demonstrators.
Reporters and protesters say Globo crews often do not wear logos identifying their network so as to avoid being assaulted.
Givalnido Manoel, a member of the leftist Socialism and Freedom Party, charged that Sao Paulo's major newspapers such as Folha de Sao Paulo and O Estado de Sao Paulo, also grossly underestimate the size of the protests.
"I walked for six hours throughout the city Monday night and there must have been at least 200,000. And the mainstream media reported 65,000. That does not make sense," he said.
On Tuesday, the area around Sao Paulo City Hall looked like a war zone as extremists stoned and tried to overturn a van of the Record television network, forcing the crew to flee before the vehicle was set ablaze.
Record later issued a statement stating the attack was the work of "a minority of vandals" and that most of the demonstrators were not to blame.
"Record reaffirms its commitment to faithfully covering the peaceful protest of thousands of people and deplores the fact that small groups are trying to impose their views through violence," the statement added.
Also Tuesday, two reporters told AFP they were covering the protest for the conservative weekly Veja, adding: "But keep it quiet. Here it's better not to say who we work for."
Celso Schroeder, president of the National Federation of Journalists, said the risk of violence against journalists comes not just from the demonstrators but also from police.
Several reporters were injured last week by police in incidents which were caught on film and which Sao Paulo authorities promised to investigate.
"You cannot equate journalists with the companies they work for. There is no question that there is a big media concentration in Brazil and this means that the companies play a political role, but one has to make a distinction between the journalists and their employers," Schroeder said.
Widespread disillusionment with mainstream media has led many young protesters to turn to Facebook, Twitter, YouTube or Instagram for news.