Trademark Infringement in Online Marketplaces and Social Media: Legal Challenges and the New Liability Framework for Digital Platforms in Brazil

Digital commerce has deeply transformed how products and services are offered to Brazilian consumers. Platforms like Mercado Livre, Shopee, and Amazon currently concentrate millions of active listings, while Instagram and TikTok have become permanent showcases for brands across diverse sectors. According to the Sebrae Small Business Pulse Survey, nearly 70% of small Brazilian entrepreneurs already sell through marketplaces, social networks, or other digital tools, exponentially expanding the field for trademark infringements. In this environment of intense circulation of goods and services, a growing legal problem has taken center stage: the unauthorized use of registered trademarks in digital environments.

Trademark infringement in the digital environment takes various forms. The commercialization of counterfeit products featuring third-party trademarks is the most well-known modality, but there is also the practice of brand bidding, in which competitors use third-party trademarks as paid search engine keywords to divert customers. Added to this is the creation of profiles and pages that simulate the visual identity of established companies, misleading consumers and causing reputational damage that is difficult to repair. Furthermore, the growth of marketplaces has brought an increase in cases of removed listings, suspended accounts, and notifications of alleged third-party rights violations, imposing practical challenges on trademark owners that current legislation does not satisfactorily address.

The Industrial Property Law (Law No. 9,279/1996) guarantees the registered trademark owner exclusive use of the mark throughout the national territory, providing civil and criminal instruments for suppressing infringements under Articles 122 to 175 and 189 to 195. However, the rule was conceived in an analog context, prior to the consolidation of e-commerce and social networks as primary distribution and communication channels. This regulatory lag poses concrete challenges to the effectiveness of trademark protection in the digital environment: types of infringements do not always fit the conduct practiced on platforms, procedural mechanisms are slow compared to the speed at which infringements spread, and jurisdictional competence can be disputed due to the cross-border nature of the involved actors.

The regulatory framework, however, is undergoing rapid transformation. In June 2025, the Supreme Federal Court (STF) declared the partial unconstitutionality of Article 19 of the Brazilian Civil Rights Framework for the Internet (Law No. 12,965/2014) during the joint trial of General Relevance Topics 533 and 987[1]. The previous model, which conditioned platform liability on a court order mandating content removal, was deemed insufficient to guarantee the protection of fundamental rights given the widespread dissemination of illicit content in the digital space. On June 17, 2026, the STF proclaimed in a plenary session the definitive legal thesis resulting from the ruling on motions for clarification filed against that decision, incorporating relevant adjustments to the original wording and concluding the trial with immediate finality (trânsito em julgado), decreed unanimously, regardless of the publication of the court ruling[2].

The definitive thesis deepens and, in several aspects, specifies the framework inaugurated in 2025. The most significant change lies in the express joint liability (responsabilidade solidária) of platforms for damages resulting from criminal or illicit third-party content under the specified conditions. The previous wording mentioned civil liability without qualifying its nature; the new thesis eliminates ambiguity by providing for joint liability, expressly applying the same rule to accounts reported as inauthentic. In contrast, the thesis incorporated a relevant safe harbor for providers: there will be no liability when providers demonstrate reasonable doubt regarding the unlawfulness of the content, provided they prove they conducted a diligent and qualified analysis before keeping the publication online[3]. This element, which was not present in the previous wording, creates a concrete incentive for adopting robust internal content review processes.

Another relevant adjustment concerns the phrasing surrounding content distributed through paid advertisements and artificial dissemination mechanisms. The previous thesis spoke of a "presumption of liability"; the new wording replaces the phrase with a "rebuttable presumption of fault," a distinction with practical impact on the burden of proof in judicial lawsuits. Terminology criteria were also adjusted: the former reference to "artificial distribution networks (chatbots or bots)" was redesignated as "artificial mechanisms of inorganic dissemination of illicit content," a more precise and technical term[4]. In both cases, the practical consequence was maintained: liability can occur regardless of prior notification, but the provider is exempted if it proves diligent action within a reasonable timeframe to make the content unavailable.

The definitive thesis also expanded the scope of application of rules on crimes against honor to cover civil torts of a similar nature—an extension relevant to the trademark field, as trademark infringements can cause damage to corporate reputation that constitutes a civil tort. Another procedural novelty was the provision of an injunctive mechanism: the party responsible for the removed content may petition the court for its reinstatement, creating an avenue for dispute that previously did not exist. The STF further specified the temporal scope of the decision's effects—ex nunc starting August 5, 2025—and set a 60-day deadline, counted from the publication of the court minutes, for providers to implement the structural obligations outlined in the thesis[5].

How this framework specifically applies to trademark infringements—and not just to crimes against honor or anti-democratic content—remains a subject of scholarly and judicial development. Trademark infringements in marketplaces and social networks constitute civil torts, and extending the new thesis to this field requires careful interpretation: it is necessary to define what constitutes a reasonable timeframe for removing infringing listings and how to handle situations where the platform claims reasonable doubt regarding ownership of the trademark involved. One point, however, received express treatment during the trial: the reporting justice clarified that platforms operating as marketplaces bear civil liability under the Consumer Defense Code, forming part of the supply chain and potentially facing joint liability with the direct supplier for seller unfitness or listing illegality[6]. This framework is particularly relevant for trademark owners, as it strengthens the avenue for holding marketplaces accountable in cases involving counterfeit product sales. Meanwhile, the rebuttable presumption of fault for paid advertisements has a direct impact on brand bidding campaigns—a practice currently widespread and rarely curbed effectively.

On an out-of-court level, platforms themselves have developed self-regulatory mechanisms that have effectively become the trademark owner's first line of defense. "Notice and takedown" systems allow for direct requests to remove infringing content or suspend listings without immediate court intervention. The STF's definitive thesis reinforces this path: providers are required to maintain notification systems complete with review procedures, due process guarantees, and dedicated service channels—preferably electronic, accessible, and widely publicized. They must also publish annual transparency reports concerning out-of-court notifications, ads, and sponsored content, creating a previously nonexistent layer of public accountability[7]. Registration with INPI (the Brazilian National Institute of Industrial Property) has become the central instrument of legitimacy for rights holders wishing to activate these mechanisms, required by platforms as a minimum criterion for recognizing ownership of verified business profiles.

From a comparative perspective, the STF's definitive thesis resembles the European model established by the Digital Services Act (DSA) and the Digital Markets Act (DMA). The DSA imposes similar structural obligations on large platforms—notably notification and takedown systems, transparency reports, and advertiser due diligence—and provides for liability in cases of failure to act following notification of illegal content. The core difference lies in the existence of a dedicated regulatory authority in Europe empowered to enforce compliance and impose administrative sanctions without requiring court intervention. In Brazil, by appealing to the Legislature to enact specific legislation and recognizing the possibility of Executive Branch regulatory action within the limits of Article 84, IV and VI(a) of the Federal Constitution, the decision signals that the current model remains transitional[8].

The most appropriate response to this regulatory gap appears to be the enactment of specific legislation. The framework established through case law, though innovative and welcome, is fragmented and relies on case-by-case interpretation, failing to offer sufficient predictability for trademark owners, platforms, and users. Specific legislation could establish clear deadlines for removing infringing trademark content, define the necessary elements for sufficient notice, establish dispute mediation mechanisms, and provide for administrative sanctions in cases of non-compliance—reducing litigation and enhancing enforcement effectiveness. Until such legislation is enacted, trademark owners must work with the tools available: solid registration with the INPI, systematic monitoring of digital channels, active use of platform notification mechanisms, thorough documentation of infringements, and, when necessary, legal action grounded in the STF's new legal thesis, whose immediate finality (trânsito em julgado), proclaimed on June 17, 2026, offers reinforced legal certainty for its application.

References

BRAZIL. Law No. 9,279 of May 14, 1996 (Industrial Property Law).

BRAZIL. Law No. 12,965 of April 23, 2014 (Civil Rights Framework for the Internet).

BRAZIL. Constitution of the Federative Republic of Brazil of 1988.

STF. RE 1,037,396 (Topic 987, Reporting Justice Min. Dias Toffoli) and RE 1,057,258 (Topic 533, Reporting Justice Min. Luiz Fux).

SEBRAE. Small Business Pulse Survey (Pesquisa Pulso dos Pequenos Negócios), 9th ed. (2025). Available at: datasebrae.com.br.

EUROPEAN UNION. Regulation (EU) 2022/2065 (Digital Services Act) and Regulation (EU) 2022/1925 (Digital Markets Act).

[1] STF. RE 1,057,258 (General Relevance Topic 533, Reporting Justice Min. Luiz Fux) and RE 1,037,396 (General Relevance Topic 987, Reporting Justice Min. Dias Toffoli), trial concluded in June 2025, recognizing the partial and progressive unconstitutionality of Article 19 of the Civil Rights Framework for the Internet.

[2] STF. Motions for clarification in RE 1,037,396 and RE 1,057,258; definitive thesis proclaimed in plenary session on June 17, 2026, with immediate finality (trânsito em julgado) unanimously decreed, regardless of the publication of the court ruling.

[3] According to the consolidated thesis, there is no strict liability: the provider avoids liability by proving reasonable doubt regarding the unlawfulness of the content, provided qualified due diligence analysis is demonstrated. The same rule applies to accounts reported as inauthentic.

[4] Regarding the replacement of "presumption of liability" with a rebuttable presumption of fault and the phrase "artificial distribution network (chatbots or bots)" with "artificial mechanisms of inorganic dissemination of illicit content," see the vote of Reporting Justice Min. Dias Toffoli on the motions for clarification. According to the reporting justice, fault-based liability prevails, requiring the interested party to prove the advertisement, damage, and causal link, while the provider must prove diligent action within a reasonable timeframe.

[5] Ex nunc modulation of effects starting August 5, 2025, excepting final unappealable decisions, and a 60-day deadline, counted from the publication of the court minutes, for implementing structural obligations.

[6] Clarification by Reporting Justice Min. Dias Toffoli in the judgment on the motions for clarification: platforms operating as marketplaces incur civil liability under the Consumer Defense Code, rather than under the general rule constructed under the Civil Code, forming part of the supply chain and potentially facing joint liability with the direct supplier for seller unfitness or listing illegality.

[7] The thesis imposes structural duties on providers: self-regulation and notification mechanisms with due process guarantees (adversarial proceedings, right of response, and the possibility of human review of automated decisions), customer service channels for users and non-users, annual transparency reports on out-of-court notifications, ads, and sponsored content, as well as a local headquarters and legal representative in the country.

[8] EUROPEAN UNION. Regulation (EU) 2022/2065 (Digital Services Act) and Regulation (EU) 2022/1925 (Digital Markets Act). Domestically, the thesis refers the enactment of specific legislation to the National Congress and recognizes the possibility of regulatory action by the Executive Branch within the limits of Article 84, IV and VI(a) of the Federal Constitution.