There is a law for everything in this country! Check out this curious report I found on the Estadão Blogs, link below, along with other historical moments for curiosity's sake:
Under the current regulations of the Samba School League, school members who get involved in disturbances can even lead to the disaffiliation of the association. In its article 23, the current rules prescribe that "inappropriate behavior by any Director or Representative of the Samba School, duly identified, at the concentration, dispersion, during the parade, or at the counting, in the sense of pressuring, threatening, or assaulting the physical or moral integrity of any member of the organization, LEAGUE, commissions, judges, or components of their own or another association" will be punished. "In the event of proof of such behavior, the Samba School will be summarily eliminated from the contest, with the consequent disaffiliation."
Sanction
Look at these stories!!
The last disturbance during the counting occurred in 2010, when members of Gaviões threw chairs and tables at the organizing committee after poor scores were announced for the 100th anniversary of Corinthians theme. The school subsequently prohibited revelers from attending the counting, but there was no more severe sanction from the organizers.
In the most serious case, in 2003, a riot caused by the Independente block – from the largest organized fan base of São Paulo – resulted in the death of carnival artist Ruy Nogueira, from the Corinthian Pavilhão 9. Independente was expelled from the carnival. When contacted, SPTuris informed that it will be up to the League to judge the current case.
Source: http://blogs.estadao.com.br/jt-cidades/regulamento-preve-expulsao-de-escola/
See the news that expelled Independente:
For the first time in 30 years of existence, Uesp (Union of Samba Schools of São Paulo) decided to eliminate a block from the São Paulo Carnival. The punishment was applied this Monday against the Independente block, which was involved in a clash of organized fan bases this weekend, during a parade at the Anhembi Sambadrome. According to the president of Uesp, Edleia dos Santos, article 16 of the block regulations provides for elimination from the Carnival and disaffiliation of the entity from the group that exhibits inappropriate behavior or practices moral aggression.
UESP is an abbreviation for Union of Samba Schools of São Paulo.
After being removed, Independente returns promising to stop being a block and become a school, read:
After a few years away from the São Paulo carnival, INDEPENDENTE is back in the carnival.
It was with great commitment and effort from the current board that we managed to return to the São Paulo carnival. But now we have returned committed to more professional work.
We will not just be a BLOCK, but a SAMBA SCHOOL, THE TORCIDA INDEPENDENTE SAMBA SCHOOL.
The current list of São Paulo schools can be found at the link: http://pt.wikipedia.org/wiki/Lista_das_escolas_de_samba_de_S%C3%A3o_Paulo whose maintenance I ignore.



