Cármen Lúcia, a minister of the Brazilian Supreme Court (STF), declared a municipal law in São Paulo unconstitutional on March 12, 2023. This law had previously relaxed the noise limits for large concerts, allowing events with prior governmental approval to bypass noise regulations and penalties under the Urban Silence Program (Psiu). Lúcia's decision upheld a prior ruling by São Paulo's judiciary, rejecting an appeal from the municipal government, led by Ricardo Nunes from the MDB party.

The controversial legislation came into effect after being approved by the São Paulo City Council in December 2024, designed to facilitate the organization of large musical events. However, it was criticized for being added as a 'jabuti'—a term referring to a legislative tactic in which unrelated provisions are included in a bill to ensure their passage. This practice raises concerns about transparency and accountability in the legislative process.

By citing existing Supreme Court jurisprudence that prohibits 'legislative smuggling', Lúcia's ruling emphasizes the need for clarity and proper legislative procedure. The implication of this decision indicates a strong stance against excessive noise pollution, balancing public enjoyment of cultural events with the rights of residents affected by such disturbances. This ruling could potentially lead to stricter regulations regarding sound levels at public events in the future.