Vargas, Lurdes2023Vargas , L 2023 , ' Hashtags na publicidade: do uso consentido ao hijacking : fronteiras entre práticas ilícitas e liberdade de expressão ' , ULP Law Review : Revista de Direito da ULP , vol. 16 , no. 1-2 . https://doi.org/10.60543/ul-plr-rdul-p.v16i1-2.87202795-5257ULP Law ReviewO que são e como funcionam os hashtags. O uso promocional dos hashtags. 2. Usar hashtags criados por outrem. Em especial, a apropriação de hashtags (hijacking). 3. Práticas comerciais desleais. 3.1. À luz do Código da Publicidade e do Regime das Práticas Comerciais Desleais. 3.2. À luz do Código de Conduta da ARP. 4. Concorrência desleal. 5. Uso ilícito de marca. 6. A sobreposição de regimes. 7. Violação de direitos de personalidade e liberdade de expressão. 7.1. Factos verdadeiros vs. factos falsos. 7.2. O interesse legítimo na divulgação de factos verdadeiros ou verídicos e a liberdade de expressão. 7.3. Opiniões pessoais, críticas agressivas e liberdade de expressão. 8. Nota final.If the birth of the hashtag is linked to individual communication, hashtags soon became a powerful tool for corporate or institutional communication. By using hashtags, a company can promote its brand more efficiently, encouraging consumers engagement; likewise, event organizers use hashtags as a privileged tool, stimulating dialogue with fans. Quite often, non-sponsors of an event want to be associated with it, giving rise to hashtags with explicit or veiled references to the event, outside its organization; hashjacking, the use of hashtags of a brand or event for purposes other than those for which they were created, such as discussing various contents or expressing negative feelings towards the brand or event, also emerges. Analysis of unwanted/authorized uses of hashtags resulted in the identification of practices of misleading advertising, unfair competition, trademark infringement and personality rights infringement, but also two large groups of lawful practices. In general, it is lawful to use hashtags with unauthorized reference to events, companies or other entities for social criticism or satire and equally lawful user-generated content that associate non-sponsors with certain events or brands. They are within the boundaries of freedom of speech.application/pdfporopenAccessPUBLICIDADEHASHTAGSCONCORRÊNCIA DESLEALLIBERDADE DE EXPRESSÃOCRIMINAL LAWFREEDOM OF SPEECHUNFAIR COMPETITIONADVERTISINGDIREITO PENALarticlehttps://doi.org/10.60543/ul-plr-rdul-p.v16i1-2.8720