A segurança pública no Estado Democrático de Direito e a regulação do espaço digital: perspectivas cidadãs, limites constitucionais e o estudo de caso do Discord no Brasil

This article examines under what conditions state intervention in transnational digital platforms, motivated by the protection of children and adolescents, is compatible with the Democratic Rule of Law and with the paradigm of citizen public security. It starts from the evolution of public security in Brazil, from authoritarian public order to a fundamental right and a positive state duty under the 1988 Constitution, and from the state duty of sufficient protection. The research is qualitative, based on literature and documents, and adopts a single case study of Discord, drawing on public sources: the 12 August 2026 notice of the National Data Protection Authority (ANPD), which suspended the live-streaming feature (Go Live) under the Digital Statute of Children and Adolescents (Law No. 15,211/2025); the public civil action filed by the Federal Government; the Federal Court decision reported in September 2026; and data from the Brazilian Public Security Yearbook 2026. It applies the proportionality test (suitability, necessity and proportionality in the strict sense), articulated with the prohibition of insufficient protection, Article 227 of the Constitution and the duty of care of platforms, recognized by the Federal Supreme Court in Theme 987. It concludes, provisionally, that a measure targeting a single feature meets the test, whereas a total block of the platform would violate it, and that citizen security in the digital environment requires transparent regulation, rather than omission or indiscriminate measures.